Add basic achievements functionality. (#7237)

* Add basic achievements functionality. This reads the mainline achievements.cfg and then all the achievements of each installed add-on. This is intentionally handled separately from other WML loading so that: a) All achievements and their status are able to be displayed on the main menu right after Wesnoth starts and regardless of which add-ons are active. b) Add-ons can add additional achievements to other content, whether UMC or mainline. For example, a modification that adds more achievements for mainline campaigns. Marking something as achieved is handled by the new [set_achieved] tag and whether an achievement has been completed can be checked via [has_achievement]. There is no attempt to prevent people from manually editing which achievements they've accomplished. NOTE: These are *not* in any way related to Steam achievements!
2023-01-21 10:32:45 -06:00 · 2023-01-21 10:32:45 -06:00 · d1465a9eb9
commit d1465a9eb9
parent 8887d9eac2
54 changed files with 1057 additions and 7 deletions
--- a/1
+++ b/1
@ -1,5 +1,6 @@
 test_fire_event
 test_gui2_iterator
+test_gui2/modal_dialog_test_achievements_dialog
 test_gui2/modal_dialog_test_addon_auth
 test_gui2/modal_dialog_test_addon_connect
 test_gui2/modal_dialog_test_addon_license_prompt
--- a/data/achievements.cfg
+++ b/data/achievements.cfg
@ -0,0 +1,97 @@
+#textdomain wesnoth
+
+# NOTE: due to achievements being loaded separately from the rest of the WML, this macro is not available for general use.
+#define ACHIEVEMENT ID NAME DESC
+#arg HIDDEN
+no#endarg
+
+#arg HIDDEN_NAME
+_"???"#endarg
+
+#arg HIDDEN_HINT
+#endarg
+
+#arg NAME_COMPLETE
+#endarg
+
+#arg DESC_COMPLETE
+#endarg
+
+#arg ICON
+data/core/images/icons/potion_red_small.png#endarg
+
+#arg ICON_COMPLETE
+data/core/images/icons/potion_green_small.png#endarg
+
+    [achievement]
+        id={ID}
+        name={NAME}
+        name_completed={NAME_COMPLETE}
+        description={DESC}
+        description_completed={DESC_COMPLETE}
+        icon={ICON}
+        icon_completed={ICON_COMPLETE}
+        hidden={HIDDEN}
+        hidden_name={HIDDEN_NAME}
+        hidden_hint={HIDDEN_HINT}
+    [/achievement]
+#enddef
+
+# some distros (ie: Debian) put campaigns in separate independent packages, so they aren't all guaranteed to exist even though they're part of mainline
+#ifhave campaigns/tutorial
+{campaigns/tutorial/achievements.cfg}
+#endif
+#ifhave campaigns/Dead_Water
+{campaigns/Dead_Water/achievements.cfg}
+#endif
+#ifhave campaigns/Delfadors_Memoirs
+{campaigns/Delfadors_Memoirs/achievements.cfg}
+#endif
+#ifhave campaigns/Descent_Into_Darkness
+{campaigns/Descent_Into_Darkness/achievements.cfg}
+#endif
+#ifhave campaigns/Eastern_Invasion
+{campaigns/Eastern_Invasion/achievements.cfg}
+#endif
+#ifhave campaigns/Heir_To_The_Throne
+{campaigns/Heir_To_The_Throne/achievements.cfg}
+#endif
+#ifhave campaigns/Legend_of_Wesmere
+{campaigns/Legend_of_Wesmere/achievements.cfg}
+#endif
+#ifhave campaigns/Liberty
+{campaigns/Liberty/achievements.cfg}
+#endif
+#ifhave campaigns/Northern_Rebirth
+{campaigns/Northern_Rebirth/achievements.cfg}
+#endif
+#ifhave campaigns/Sceptre_of_Fire
+{campaigns/Sceptre_of_Fire/achievements.cfg}
+#endif
+#ifhave campaigns/Secrets_of_the_Ancients
+{campaigns/Secrets_of_the_Ancients/achievements.cfg}
+#endif
+#ifhave campaigns/Son_Of_The_Black_Eye
+{campaigns/Son_Of_The_Black_Eye/achievements.cfg}
+#endif
+#ifhave campaigns/The_Hammer_of_Thursagan
+{campaigns/The_Hammer_of_Thursagan/achievements.cfg}
+#endif
+#ifhave campaigns/The_Rise_Of_Wesnoth
+{campaigns/The_Rise_Of_Wesnoth/achievements.cfg}
+#endif
+#ifhave campaigns/The_South_Guard
+{campaigns/The_South_Guard/achievements.cfg}
+#endif
+#ifhave campaigns/Two_Brothers
+{campaigns/Two_Brothers/achievements.cfg}
+#endif
+#ifhave campaigns/Under_the_Burning_Suns
+{campaigns/Under_the_Burning_Suns/achievements.cfg}
+#endif
+#ifhave campaigns/Winds_of_Fate
+{campaigns/Winds_of_Fate/achievements.cfg}
+#endif
+#ifhave campaigns/World_Conquest
+{campaigns/World_Conquest/achievements.cfg}
+#endif
--- a/data/campaigns/Dead_Water/achievements.cfg
+++ b/data/campaigns/Dead_Water/achievements.cfg
--- a/data/campaigns/Delfadors_Memoirs/achievements.cfg
+++ b/data/campaigns/Delfadors_Memoirs/achievements.cfg
--- a/data/campaigns/Descent_Into_Darkness/achievements.cfg
+++ b/data/campaigns/Descent_Into_Darkness/achievements.cfg
@ -0,0 +1,5 @@
+[achievement_group]
+    display_name=_"Descent into Darkness"
+    content_for=descent_into_darkness
+    {ACHIEVEMENT "did_rat_eater" _"Rat Eater" _"Have a Ghoul eat way too many rats during Descent into Darkness's A Haunting in Winter." HIDDEN=yes HIDDEN_HINT=_"Eat some rats!"}
+[/achievement_group]
--- a/data/campaigns/Descent_Into_Darkness/scenarios/03_A_Haunting_in_Winter.cfg
+++ b/data/campaigns/Descent_Into_Darkness/scenarios/03_A_Haunting_in_Winter.cfg
@ -1206,6 +1206,11 @@
            speaker=Malin Keshar
            message= _ "I must be absolutely mad to be spending hours here just feeding rats to this rotten pile of flesh..."
        [/message]
+
+        [set_achieved]
+            content_for="Descent into Darkness"
+            id="did_rat_eater"
+        [/set_achieved]
    [/event]
    [event]
        name=rat eating2
--- a/data/campaigns/Eastern_Invasion/achievements.cfg
+++ b/data/campaigns/Eastern_Invasion/achievements.cfg
--- a/data/campaigns/Heir_To_The_Throne/achievements.cfg
+++ b/data/campaigns/Heir_To_The_Throne/achievements.cfg
--- a/data/campaigns/Legend_of_Wesmere/achievements.cfg
+++ b/data/campaigns/Legend_of_Wesmere/achievements.cfg
--- a/data/campaigns/Liberty/achievements.cfg
+++ b/data/campaigns/Liberty/achievements.cfg
--- a/data/campaigns/Northern_Rebirth/achievements.cfg
+++ b/data/campaigns/Northern_Rebirth/achievements.cfg
--- a/data/campaigns/Sceptre_of_Fire/achievements.cfg
+++ b/data/campaigns/Sceptre_of_Fire/achievements.cfg
--- a/data/campaigns/Secrets_of_the_Ancients/achievements.cfg
+++ b/data/campaigns/Secrets_of_the_Ancients/achievements.cfg
--- a/data/campaigns/Son_Of_The_Black_Eye/achievements.cfg
+++ b/data/campaigns/Son_Of_The_Black_Eye/achievements.cfg
--- a/data/campaigns/The_Hammer_of_Thursagan/achievements.cfg
+++ b/data/campaigns/The_Hammer_of_Thursagan/achievements.cfg
--- a/data/campaigns/The_Rise_Of_Wesnoth/achievements.cfg
+++ b/data/campaigns/The_Rise_Of_Wesnoth/achievements.cfg
--- a/data/campaigns/The_South_Guard/achievements.cfg
+++ b/data/campaigns/The_South_Guard/achievements.cfg
--- a/data/campaigns/Two_Brothers/achievements.cfg
+++ b/data/campaigns/Two_Brothers/achievements.cfg
--- a/data/campaigns/Under_the_Burning_Suns/achievements.cfg
+++ b/data/campaigns/Under_the_Burning_Suns/achievements.cfg
--- a/data/campaigns/Winds_of_Fate/achievements.cfg
+++ b/data/campaigns/Winds_of_Fate/achievements.cfg
--- a/data/campaigns/World_Conquest/achievements.cfg
+++ b/data/campaigns/World_Conquest/achievements.cfg
--- a/data/campaigns/tutorial/achievements.cfg
+++ b/data/campaigns/tutorial/achievements.cfg
@ -0,0 +1,5 @@
+[achievement_group]
+    display_name=_"Tutorial"
+    content_for=tutorial
+    {ACHIEVEMENT "completed" _"Complete the Tutorial" _"Complete all scenarios of the Tutorial campaign."}
+[/achievement_group]
--- a/data/campaigns/tutorial/scenarios/02_Tutorial_part_2.cfg
+++ b/data/campaigns/tutorial/scenarios/02_Tutorial_part_2.cfg
@ -1498,6 +1498,11 @@ Rest-healing is an exception to the rule — if a unit doesn’t do anything for
            message= _ "You can also refer to the in-game help browser if you ever need to refresh your memory on gameplay mechanics."
        [/message]

+        [set_achieved]
+            content_for="Tutorial"
+            id="tutorial_finished"
+        [/set_achieved]
+
        {CLEAR_VARIABLE low_hp_unit_message,lhpu_msg_i}
        {CLEAR_VARIABLE spoke_about_income,spoke_about_orcs_crossing_river}
        {CLEAR_VARIABLE undo_option}
--- a/data/core/hotkeys.cfg
+++ b/data/core/hotkeys.cfg
@ -57,6 +57,12 @@
    key=a
    {IF_APPLE_CMD_ELSE_CTRL}
 [/hotkey]
+[hotkey]
+    command=achievements
+    key=a
+    shift=yes
+    {IF_APPLE_CMD_ELSE_CTRL}
+[/hotkey]
 [hotkey]
    command=bestenemymoves
    key=b
--- a/data/gui/window/achievements_dialog.cfg
+++ b/data/gui/window/achievements_dialog.cfg
@ -0,0 +1,220 @@
+#textdomain wesnoth-lib
+###
+### Definition of the window for showing achievements and their statuses
+###
+
+[window]
+	id = "achievements_dialog"
+	description = "Dialog for displaying achievements and their statuses"
+
+	[resolution]
+		definition = "default"
+
+		automatic_placement = true
+		vertical_placement = "center"
+		horizontal_placement = "center"
+
+		maximum_width = 800
+
+		[tooltip]
+			id = "tooltip"
+		[/tooltip]
+
+		[helptip]
+			id = "tooltip"
+		[/helptip]
+
+		[linked_group]
+			id = "achievements"
+			fixed_width = true
+			fixed_height = true
+		[/linked_group]
+
+		[grid]
+
+			[row]
+				[column]
+					horizontal_grow = true
+					[grid]
+						[row]
+							[column]
+								grow_factor = 1
+			
+								border = "all"
+								border_size = 5
+								horizontal_alignment = "left"
+								[label]
+									definition = "title"
+			
+									label = _ "Achievements"
+								[/label]
+			
+							[/column]
+
+							[column]
+								horizontal_alignment = "right"
+								grow_factor = 0
+
+								border = "all"
+								border_size = 5
+
+								[label]
+									definition = "default"
+									label = _ "Content:"
+								[/label]
+
+							[/column]
+							
+							[column]
+								horizontal_alignment = "right"
+								grow_factor = 0
+								border = "all"
+								border_size = 5
+
+								[menu_button]
+									id = "selected_achievements_list"
+									definition = "default"
+								[/menu_button]
+
+							[/column]
+						[/row]
+					[/grid]
+				[/column]
+			[/row]
+
+			[row]
+				grow_factor = 1
+
+				[column]
+					grow_factor = 1
+					border = "all"
+					border_size = 5
+
+					{GUI_FORCE_WIDGET_MINIMUM_SIZE 600 480 (
+						[listbox]
+							id = "achievements_list"
+
+							vertical_scrollbar_mode = "always"
+							horizontal_scrollbar_mode = "never"
+					
+							[list_definition]
+					
+								[row]
+					
+									[column]
+										horizontal_grow = true
+
+										[toggle_panel]
+											id = "panel"
+											definition = "default"
+											linked_group = "achievements"
+					
+											[grid]
+												[row]
+													[column]
+														grow_factor = 0
+														horizontal_grow = false
+														vertical_alignment = "center"
+														horizontal_alignment = "left"
+												
+														border = "all"
+														border_size = 5
+												
+														[drawing]
+															id = "icon"
+															definition = "default"
+												
+															width = 72
+															height = 72
+												
+															[draw]
+												
+																[image]
+																	name = "(text)"
+																	w = "(min(image_original_width, 60))"
+																	h = "(min(image_original_height, 60))"
+												
+																	{GUI_CENTERED_IMAGE}
+																[/image]
+												
+															[/draw]
+												
+														[/drawing]
+												
+													[/column]
+
+													[column]
+														grow_factor = 1
+														horizontal_alignment = "left"
+														[grid]
+															[row]
+																[column]
+																	grow_factor = 1
+																	border = "all"
+																	border_size = 5
+																	horizontal_alignment = "left"
+					
+																	[label]
+																		id = "name"
+																		definition = "default_large"
+																		use_markup = true
+																	[/label]
+																[/column]
+															[/row]
+
+															[row]
+																[column]
+																	grow_factor = 1
+																	border = "all"
+																	border_size = 5
+																	horizontal_alignment = "left"
+					
+																	[label]
+																		id = "description"
+																		definition = "default_small"
+																		characters_per_line = 70
+																		use_markup = true
+																	[/label]
+																[/column]
+															[/row]
+														[/grid]
+													[/column]
+												[/row]
+											[/grid]
+										[/toggle_panel]
+
+									[/column]
+								[/row]
+
+							[/list_definition]
+						[/listbox]
+					)}
+				
+				[/column]
+			
+			[/row]
+
+			[row]
+				grow_factor = 0
+
+				[column]
+					border = "all"
+					border_size = 5
+					horizontal_alignment = "right"
+
+					[button]
+						id = "ok"
+						definition = "default"
+
+						label = _ "OK"
+					[/button]
+
+				[/column]
+
+			[/row]
+
+		[/grid]
+
+	[/resolution]
+
+[/window]
--- a/data/lua/wml-conditionals.lua
+++ b/data/lua/wml-conditionals.lua
@ -38,3 +38,7 @@ function wesnoth.wml_conditionals.variable(cfg)
 		return old_variable(cfg)
 	end
 end
+
+function wesnoth.wml_conditionals.has_achievement(cfg)
+	return wesnoth.achievements.has(cfg.content_for, cfg.id);
+end
--- a/data/lua/wml-tags.lua
+++ b/data/lua/wml-tags.lua
@ -1011,3 +1011,12 @@ function wml_actions.remove_trait(cfg)
 		unit:remove_modifications({id = obj_id}, "trait")
 	end
 end
+
+function wml_actions.set_achievement(cfg)
+	local achievement = wesnoth.achievements.get(cfg.content_for, cfg.id)
+	-- don't show the achievement popup for an achievement they already have
+	if not achievement.achieved then
+		wesnoth.achievements.set(cfg.content_for, cfg.id)
+		gui.show_popup(achievement.name_completed, achievement.description_completed, achievement.icon_completed)
+	end
+end
--- a/data/schema/achievements.cfg
+++ b/data/schema/achievements.cfg
@ -0,0 +1,27 @@
+[wml_schema]
+	{./macros.cfg}
+	{./types/basic.cfg}
+	[tag]
+		name="root"
+		[tag]
+			name="achievement_group"
+			max="infinite"
+			{REQUIRED_KEY content_for string}
+			{REQUIRED_KEY display_name t_string}
+			[tag]
+				name="achievement"
+				max="infinite"
+				{REQUIRED_KEY id string}
+				{REQUIRED_KEY name t_string}
+				{SIMPLE_KEY name_completed t_string}
+				{REQUIRED_KEY description t_string}
+				{SIMPLE_KEY description_completed t_string}
+				{REQUIRED_KEY icon string}
+				{SIMPLE_KEY icon_completed string}
+				{SIMPLE_KEY hidden bool}
+				{SIMPLE_KEY hidden_name t_string}
+				{SIMPLE_KEY hidden_hint t_string}
+			[/tag]
+		[/tag]
+	[/tag]
+[/wml_schema]
--- a/data/test/scenarios/wml_tests/ScenarioWML/EventWML/ActionWML/ConditionalActionsWML/has_achievement.cfg
+++ b/data/test/scenarios/wml_tests/ScenarioWML/EventWML/ActionWML/ConditionalActionsWML/has_achievement.cfg
@ -0,0 +1,36 @@
+#####
+# API(s) being tested: [has_achievement]
+#####
+{GENERIC_UNIT_TEST "has_achievement" (
+    [event]
+        name = start
+
+        [if]
+            [has_achievement]
+                content_for=tutorial
+                id=completed
+            [/has_achievement]
+            [then]
+                {FAIL}
+            [/then]
+        [/if]
+
+        [set_achievement]
+            content_for=tutorial
+            id=completed
+        [/set_achievement]
+
+        [if]
+            [has_achievement]
+                content_for=tutorial
+                id=completed
+            [/has_achievement]
+            [then]
+                {SUCCEED}
+            [/then]
+            [else]
+                {FAIL}
+            [/else]
+        [/if]
+    [/event]
+)}
--- a/projectfiles/CodeBlocks/tests.cbp
+++ b/projectfiles/CodeBlocks/tests.cbp
@ -100,6 +100,8 @@
 		</Unit>
 		<Unit filename="../../src/about.cpp" />
 		<Unit filename="../../src/about.hpp" />
+		<Unit filename="../../src/achievements.cpp" />
+		<Unit filename="../../src/achievements.hpp" />
 		<Unit filename="../../src/actions/advancement.cpp" />
 		<Unit filename="../../src/actions/advancement.hpp" />
 		<Unit filename="../../src/actions/attack.cpp" />
@ -565,6 +567,8 @@
 		<Unit filename="../../src/gui/core/window_builder/helper.hpp" />
 		<Unit filename="../../src/gui/core/window_builder/instance.cpp" />
 		<Unit filename="../../src/gui/core/window_builder/instance.hpp" />
+		<Unit filename="../../src/gui/dialogs/achievements_dialog.cpp" />
+		<Unit filename="../../src/gui/dialogs/achievements_dialog.hpp" />
 		<Unit filename="../../src/gui/dialogs/addon/addon_auth.cpp" />
 		<Unit filename="../../src/gui/dialogs/addon/addon_auth.hpp" />
 		<Unit filename="../../src/gui/dialogs/addon/connect.cpp" />
--- a/projectfiles/CodeBlocks/wesnoth.cbp
+++ b/projectfiles/CodeBlocks/wesnoth.cbp
@ -98,6 +98,8 @@
 		</Unit>
 		<Unit filename="../../src/about.cpp" />
 		<Unit filename="../../src/about.hpp" />
+		<Unit filename="../../src/achievements.cpp" />
+		<Unit filename="../../src/achievements.hpp" />
 		<Unit filename="../../src/actions/advancement.cpp" />
 		<Unit filename="../../src/actions/advancement.hpp" />
 		<Unit filename="../../src/actions/attack.cpp" />
@ -560,6 +562,8 @@
 		<Unit filename="../../src/gui/core/window_builder/helper.hpp" />
 		<Unit filename="../../src/gui/core/window_builder/instance.cpp" />
 		<Unit filename="../../src/gui/core/window_builder/instance.hpp" />
+		<Unit filename="../../src/gui/dialogs/achievements_dialog.cpp" />
+		<Unit filename="../../src/gui/dialogs/achievements_dialog.hpp" />
 		<Unit filename="../../src/gui/dialogs/addon/addon_auth.cpp" />
 		<Unit filename="../../src/gui/dialogs/addon/addon_auth.hpp" />
 		<Unit filename="../../src/gui/dialogs/addon/connect.cpp" />
--- a/Wesnoth.xcodeproj/project.pbxproj
+++ b/Wesnoth.xcodeproj/project.pbxproj
@ -8,7 +8,11 @@

 /* Begin PBXBuildFile section */
 		1234567890ABCDEF12345678 /* file_progress.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1234567890ABCDEF12345680 /* file_progress.cpp */; };
+		000000000000000000000005 /* achievements.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 000000000000000000000001 /* achievements.cpp */; };
+		000000000000000000000006 /* achievements_dialog.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 000000000000000000000003 /* achievements_dialog.cpp */; };
 		1234567890ABCDEF12345679 /* file_progress.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1234567890ABCDEF12345680 /* file_progress.cpp */; };
+		000000000000000000000007 /* achievements.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 000000000000000000000001 /* achievements.cpp */; };
+		000000000000000000000008 /* achievements_dialog.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 000000000000000000000003 /* achievements_dialog.cpp */; };
 		36B146FAA79A55E9F43723B1 /* general.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 84234C54BB84519421FD4136 /* general.cpp */; };
 		4291489DA38012477DA3BA7C /* general.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 84234C54BB84519421FD4136 /* general.cpp */; };
 		3C254DF5B7DF196F2041955F /* mp_report.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 58C649488B3014E6F7254B62 /* mp_report.cpp */; };
@ -1498,6 +1502,10 @@
 		1058C7A1FEA54F0111CA2CBB /* Cocoa.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Cocoa.framework; path = System/Library/Frameworks/Cocoa.framework; sourceTree = SDKROOT; };
 		1234567890ABCDEF12345680 /* file_progress.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = file_progress.cpp; sourceTree = "<group>"; };
 		1234567890ABCDEF12345681 /* file_progress.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = file_progress.hpp; sourceTree = "<group>"; };
+		000000000000000000000001 /* achievements.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = achievements.cpp; sourceTree = "<group>"; };
+		000000000000000000000002 /* achievements.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = achievements.hpp; sourceTree = "<group>"; };
+		000000000000000000000003 /* achievements_dialog.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = achievements_dialog.cpp; sourceTree = "<group>"; };
+		000000000000000000000004 /* achievements_dialog.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = achievements_dialog.hpp; sourceTree = "<group>"; };
 		1C58BBDF21822A930078D25A /* Security.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Security.framework; path = System/Library/Frameworks/Security.framework; sourceTree = SDKROOT; };
 		460D897824DC7830000B1ABC /* game.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = game.cpp; path = ../../src/server/wesnothd/game.cpp; sourceTree = SOURCE_ROOT; };
 		460D897924DC7830000B1ABC /* ban.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; name = ban.hpp; path = ../../src/server/wesnothd/ban.hpp; sourceTree = SOURCE_ROOT; };
@ -3095,6 +3103,8 @@
 			children = (
 				B5599AC60EC62181008DD061 /* about.cpp */,
 				B5599ABC0EC62181008DD061 /* about.hpp */,
+				000000000000000000000001 /* achievements.cpp */,
+				000000000000000000000002 /* achievements.hpp */,
 				620A386115E9364E00A4F513 /* actions */,
 				B52EE9A81213640400CFBDAB /* addon */,
 				B597EBCA0FC082AB00CE81F5 /* ai */,
@ -3637,6 +3647,8 @@
 				46F92C842174F6A300602C1C /* file_dialog.hpp */,
 				1234567890ABCDEF12345680 /* file_progress.cpp */,
 				1234567890ABCDEF12345681 /* file_progress.hpp */,
+				000000000000000000000003 /* achievements_dialog.cpp */,
+				000000000000000000000004 /* achievements_dialog.hpp */,
 				46F92C6E2174F6A300602C1C /* folder_create.cpp */,
 				46F92C8A2174F6A300602C1C /* folder_create.hpp */,
 				46F92CBB2174F6A300602C1C /* formula_debugger.cpp */,
@ -5514,6 +5526,8 @@
 				B52EE8D7121359A600CFBDAB /* persist_manager.cpp in Sources */,
 				46F92DBB2174F6A300602C1C /* file_dialog.cpp in Sources */,
 				1234567890ABCDEF12345678 /* file_progress.cpp in Sources */,
+				000000000000000000000005 /* achievements.cpp in Sources */,
+				000000000000000000000006 /* achievements_dialog.cpp in Sources */,
 				46F92F0F2174FEC000602C1C /* standard_colors.cpp in Sources */,
 				46F92E852174F6A400602C1C /* debug.cpp in Sources */,
 				B52EE8D8121359A600CFBDAB /* persist_var.cpp in Sources */,
@ -6137,6 +6151,8 @@
 				91E3570A1CACC9B200774252 /* playcampaign.cpp in Sources */,
 				46F92DBC2174F6A300602C1C /* file_dialog.cpp in Sources */,
 				1234567890ABCDEF12345679 /* file_progress.cpp in Sources */,
+				000000000000000000000007 /* achievements.cpp in Sources */,
+				000000000000000000000008 /* achievements_dialog.cpp in Sources */,
 				91E3570B1CACC9B200774252 /* singleplayer.cpp in Sources */,
 				4649B88B20288EEF00827CFB /* surface.cpp in Sources */,
 				46F92DB02174F6A300602C1C /* campaign_selection.cpp in Sources */,
--- a/source_lists/wesnoth
+++ b/source_lists/wesnoth
@ -1,4 +1,5 @@
 about.cpp
+achievements.cpp
 actions/advancement.cpp
 actions/attack.cpp
 actions/create.cpp
@ -172,6 +173,7 @@ gui/dialogs/addon/install_dependencies.cpp
 gui/dialogs/addon/license_prompt.cpp
 gui/dialogs/addon/manager.cpp
 gui/dialogs/addon/uninstall_list.cpp
+gui/dialogs/achievements_dialog.cpp
 gui/dialogs/attack_predictions.cpp
 gui/dialogs/campaign_difficulty.cpp
 gui/dialogs/campaign_selection.cpp
--- a/src/achievements.cpp
+++ b/src/achievements.cpp
@ -0,0 +1,108 @@
+/*
+	Copyright (C) 2003 - 2022
+	by David White <dave@whitevine.net>
+	Part of the Battle for Wesnoth Project https://www.wesnoth.org/
+
+	This program is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY.
+
+	See the COPYING file for more details.
+*/
+
+#include "achievements.hpp"
+
+#include "filesystem.hpp"
+#include "game_config.hpp"
+#include "log.hpp"
+#include "preferences/general.hpp"
+#include "serialization/parser.hpp"
+#include "serialization/preprocessor.hpp"
+
+static lg::log_domain log_config("config");
+#define ERR_CONFIG LOG_STREAM(err, log_config)
+
+/**
+ * Reads the mainline achievements.cfg and then all the achievements of each installed add-on.
+ *
+ * This is intentionally handled separately from other WML loading so that:
+ * a) All achievements and their status are able to be displayed on the main menu right after Wesnoth starts and regardless of which add-ons are active.
+ * b) Add-ons can add additional achievements to other content, whether UMC or mainline. For example, a modification that adds more achievements for mainline campaigns.
+ *
+ * NOTE: These are *not* in any way related to Steam achievements!
+ */
+achievements::achievements()
+	: achievement_list_()
+{
+	// mainline
+	try {
+		config cfg = read_achievements_file(game_config::path + "/data/achievements.cfg");
+		process_achievements_file(cfg, "Mainline");
+	} catch(const game::error& e) {
+		ERR_CONFIG << "Error processing mainline achievements, ignoring: " << e.what();
+	}
+
+	// add-ons
+	std::vector<std::string> dirs;
+	filesystem::get_files_in_dir(filesystem::get_addons_dir(), nullptr, &dirs);
+	for(const std::string& dir : dirs) {
+		try {
+			config cfg = read_achievements_file(filesystem::get_addons_dir() + "/" + dir + "/achievements.cfg");
+			process_achievements_file(cfg, dir);
+		} catch(const game::error& e) {
+			ERR_CONFIG << "Error processing add-on " << dir << " achievements, ignoring: " << e.what();
+		}
+	}
+}
+
+/**
+ * Reads an achievements.cfg file into a config.
+ *
+ * @param path The path to the achievements.cfg file.
+ * @return The config containing all the achievements.
+ */
+config achievements::read_achievements_file(const std::string& path)
+{
+	config cfg;
+	if(filesystem::file_exists(path)) {
+		filesystem::scoped_istream stream = preprocess_file(path);
+		read(cfg, *stream);
+	}
+	return cfg;
+}
+
+/**
+ * Processes a config object to add new achievements to @a achievement_list_.
+ *
+ * @param cfg The config containing additional achievements.
+ * @param content_source The source of the additional achievements - either mainline or an add-on.
+ */
+void achievements::process_achievements_file(const config& cfg, const std::string& content_source)
+{
+	for(const config& achgrp : cfg.child_range("achievement_group")) {
+		if(achgrp["content_for"].str().empty()) {
+			ERR_CONFIG << content_source + " achievement_group missing content_for attribute:\n" << achgrp.debug();
+			continue;
+		}
+		achievement_list_.emplace_back(achgrp);
+	}
+}
+
+achievement_group::achievement_group(const config& cfg)
+	: display_name_(cfg["display_name"].t_str())
+	, content_for_(cfg["content_for"].str())
+	, achievements_()
+{
+	for(const config& ach : cfg.child_range("achievement")) {
+		std::string id = ach["id"].str();
+
+		if(id.empty()) {
+			ERR_CONFIG << content_for_ + " achievement missing id attribute:\n" << ach.debug();
+		} else {
+			achievements_.emplace_back(ach, preferences::achievement(content_for_, id));
+		}
+	}
+}
--- a/src/achievements.hpp
+++ b/src/achievements.hpp
@ -0,0 +1,110 @@
+/*
+	Copyright (C) 2003 - 2022
+	by David White <dave@whitevine.net>
+	Part of the Battle for Wesnoth Project https://www.wesnoth.org/
+
+	This program is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY.
+
+	See the COPYING file for more details.
+*/
+
+#pragma once
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "config.hpp"
+#include "tstring.hpp"
+
+/**
+ * Represents a single achievement and its data.
+ */
+struct achievement
+{
+	/** The ID of the achievement. Must be unique per achievement_group */
+	std::string id_;
+	/** The name of the achievement to show on the UI. */
+	t_string name_;
+	/** The name of the achievement to show on the UI if the achievement is completed. */
+	t_string name_completed_;
+	/** The description of the achievement to show on the UI. */
+	t_string description_;
+	/** The name of the achievement to show on the UI if the achievement is completed. */
+	t_string description_completed_;
+	/** The icon of the achievement to show on the UI. */
+	std::string icon_;
+	/** The icon of the achievement to show on the UI if the achievement is completed. */
+	std::string icon_completed_;
+	/** Whether to show the achievement's actual name and description on the UI before it's been completed. */
+	bool hidden_;
+	/** The hint to display in place of the description if the achievement is hidden and uncompleted */
+	t_string hidden_name_;
+	/** The hint to display in place of the description if the achievement is hidden and uncompleted */
+	t_string hidden_hint_;
+	/** Whether the achievement has been completed. */
+	bool achieved_;
+
+	achievement(const config& cfg, bool achieved)
+		: id_(cfg["id"].str())
+		, name_(cfg["name"].t_str())
+		, name_completed_(cfg["name_completed"].t_str())
+		, description_(cfg["description"].t_str())
+		, description_completed_(cfg["description_completed"].t_str())
+		, icon_(cfg["icon"].str()+"~GS()")
+		, icon_completed_(cfg["icon_completed"].str())
+		, hidden_(cfg["hidden"].to_bool())
+		, hidden_name_(cfg["hidden_name"].t_str())
+		, hidden_hint_(cfg["hidden_hint"].t_str())
+		, achieved_(achieved)
+	{
+		if(name_completed_.empty()) {
+			name_completed_ = name_;
+		}
+		if(description_completed_.empty()) {
+			description_completed_ = description_;
+		}
+		if(icon_completed_.empty()) {
+			icon_completed_ = icon_;
+		}
+	}
+};
+
+/**
+ * A set of achievements tied to a particular content. Achievements can be added to any content from any add-on, even if it's entirely unrelated.
+ */
+struct achievement_group
+{
+	/** The name of the content to display on the UI. */
+	t_string display_name_;
+	/** The internal ID used for this content. */
+	std::string content_for_;
+	/** The achievements associated to this content. */
+	std::vector<achievement> achievements_;
+
+	achievement_group(const config& cfg);
+};
+
+/**
+ * This class is responsible for reading all available achievements from mainline's and any add-ons' achievements.cfg files for use in achievements_dialog.
+ */
+class achievements
+{
+public:
+	achievements();
+	std::vector<achievement_group>& get_list()
+	{
+		return achievement_list_;
+	}
+
+private:
+	config read_achievements_file(const std::string& path);
+	void process_achievements_file(const config& cfg, const std::string& content_source);
+
+	std::vector<achievement_group> achievement_list_;
+};
--- a/src/game_config_manager.cpp
+++ b/src/game_config_manager.cpp
@ -61,6 +61,7 @@ game_config_manager::game_config_manager(const commandline_options& cmdline_opts
 	, old_defines_map_()
 	, paths_manager_()
 	, cache_(game_config::config_cache::instance())
+	, achievements_()
 {
 	assert(!singleton);
 	singleton = this;
--- a/src/game_config_manager.hpp
+++ b/src/game_config_manager.hpp
@ -15,12 +15,14 @@

 #pragma once

+#include "achievements.hpp"
 #include "commandline_options.hpp"
 #include "config.hpp"
 #include "config_cache.hpp"
 #include "filesystem.hpp"
 #include "game_config_view.hpp"
 #include "terrain/type_data.hpp"
+
 #include <optional>

 class game_classification;
@ -42,7 +44,8 @@ public:

 	const game_config_view& game_config() const { return game_config_view_; }
 	const preproc_map& old_defines_map() const { return old_defines_map_; }
-	const std::shared_ptr<terrain_type_data> & terrain_types() const { return tdata_; }
+	const std::shared_ptr<terrain_type_data>& terrain_types() const { return tdata_; }
+	std::vector<achievement_group>& get_achievements() { return achievements_.get_list(); }

 	bool init_game_config(FORCE_RELOAD_CONFIG force_reload);
 	void reload_changed_game_config();
@ -84,4 +87,6 @@ private:
 	game_config::config_cache& cache_;

 	std::shared_ptr<terrain_type_data> tdata_;
+
+	achievements achievements_;
 };
--- a/src/game_events/action_wml.cpp
+++ b/src/game_events/action_wml.cpp
@ -43,6 +43,7 @@
 #include "pathfind/pathfind.hpp"
 #include "persist_var.hpp"
 #include "play_controller.hpp"
+#include "preferences/general.hpp"
 #include "recall_list_manager.hpp"
 #include "replay.hpp"
 #include "random.hpp"
@ -239,16 +240,16 @@ wml_action::wml_action(const std::string & tag, handler function)
 *
 * Generated code looks like this:
 * \code
- * void wml_func_foo(...);
+ * static void wml_func_foo(...);
 * static wml_action wml_action_foo("foo", &wml_func_foo);
- * void wml_func_foo(...)
+ * static void wml_func_foo(...)
 * {
 *    // code for foo
 * }
 * \endcode
 */
 #define WML_HANDLER_FUNCTION(pname, pei, pcfg) \
-	static void wml_func_##pname(const queued_event &pei, const vconfig &pcfg); \
+	static void wml_func_##pname(const queued_event& pei, const vconfig& pcfg); \
 	static wml_action wml_action_##pname(#pname, &wml_func_##pname);  \
 	static void wml_func_##pname(const queued_event& pei, const vconfig& pcfg)

--- a/src/game_events/conditional_wml.cpp
+++ b/src/game_events/conditional_wml.cpp
@ -24,6 +24,7 @@
 #include "game_board.hpp"
 #include "game_data.hpp"
 #include "log.hpp"
+#include "preferences/general.hpp"
 #include "recall_list_manager.hpp"
 #include "resources.hpp"
 #include "scripting/game_lua_kernel.hpp"
--- a/src/gui/dialogs/achievements_dialog.cpp
+++ b/src/gui/dialogs/achievements_dialog.cpp
@ -0,0 +1,125 @@
+/*
+	Copyright (C) 2003 - 2022
+	by David White <dave@whitevine.net>
+	Part of the Battle for Wesnoth Project https://www.wesnoth.org/
+
+	This program is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY.
+
+	See the COPYING file for more details.
+*/
+
+#define GETTEXT_DOMAIN "wesnoth-lib"
+
+#include "gui/dialogs/achievements_dialog.hpp"
+
+#include "game_config_manager.hpp"
+#include "gettext.hpp"
+#include "gui/auxiliary/find_widget.hpp"
+#include "gui/widgets/window.hpp"
+#include "log.hpp"
+
+namespace gui2::dialogs
+{
+
+REGISTER_DIALOG(achievements_dialog)
+
+achievements_dialog::achievements_dialog()
+	: modal_dialog(window_id())
+	, achieve_()
+	, achievements_box_(nullptr)
+	, content_names_(nullptr)
+{
+}
+
+void achievements_dialog::pre_show(window& win)
+{
+	std::vector<config> content_list;
+	content_names_ = &find_widget<menu_button>(&win, "selected_achievements_list", false);
+	connect_signal_notify_modified(*content_names_, std::bind(&achievements_dialog::set_achievements_content, this));
+
+	achievements_box_ = find_widget<listbox>(&win, "achievements_list", false, true);
+
+auto* a = game_config_manager::get();
+auto b = a->get_achievements();
+	for(const auto& list : b) {
+		// populate all possibilities into the dropdown
+		content_list.emplace_back("label", list.display_name_);
+
+		// only display the achievements for the first dropdown option on first showing the dialog
+		if(content_list.size() == 1) {
+			for(const auto& ach : list.achievements_) {
+				widget_data row;
+				widget_item item;
+
+				item["label"] = !ach.achieved_ ? ach.icon_ : ach.icon_completed_;
+				row.emplace("icon", item);
+
+				if(ach.hidden_ && !ach.achieved_) {
+					item["label"] = ach.hidden_name_;
+				} else if(!ach.achieved_) {
+					item["label"] = ach.name_;
+				} else {
+					item["label"] = "<span color='green'>"+ach.name_completed_+"</span>";
+				}
+				row.emplace("name", item);
+
+				if(ach.hidden_ && !ach.achieved_) {
+					item["label"] = ach.hidden_hint_;
+				} else if(!ach.achieved_) {
+					item["label"] = ach.description_;
+				} else {
+					item["label"] = "<span color='green'>"+ach.description_completed_+"</span>";
+				}
+				row.emplace("description", item);
+
+				achievements_box_->add_row(row);
+			}
+		}
+	}
+	if(content_list.size() > 0) {
+		content_names_->set_values(content_list);
+	}
+}
+
+void achievements_dialog::post_show(window&)
+{
+}
+
+void achievements_dialog::set_achievements_content()
+{
+	achievements_box_->clear();
+	for(const auto& ach : game_config_manager::get()->get_achievements().at(content_names_->get_value()).achievements_) {
+		widget_data row;
+		widget_item item;
+
+		item["label"] = !ach.achieved_ ? ach.icon_ : ach.icon_completed_;
+		row.emplace("icon", item);
+
+		if(ach.hidden_ && !ach.achieved_) {
+			item["label"] = ach.hidden_name_;
+		} else if(!ach.achieved_) {
+			item["label"] = ach.name_;
+		} else {
+			item["label"] = "<span color='green'>"+ach.name_completed_+"</span>";
+		}
+		row.emplace("name", item);
+
+		if(ach.hidden_ && !ach.achieved_) {
+			item["label"] = ach.hidden_hint_;
+		} else if(!ach.achieved_) {
+			item["label"] = ach.description_;
+		} else {
+			item["label"] = "<span color='green'>"+ach.description_completed_+"</span>";
+		}
+		row.emplace("description", item);
+
+		achievements_box_->add_row(row);
+	}
+}
+
+} // namespace gui2::dialogs
--- a/src/gui/dialogs/achievements_dialog.hpp
+++ b/src/gui/dialogs/achievements_dialog.hpp
@ -0,0 +1,59 @@
+/*
+	Copyright (C) 2003 - 2022
+	by David White <dave@whitevine.net>
+	Part of the Battle for Wesnoth Project https://www.wesnoth.org/
+
+	This program is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY.
+
+	See the COPYING file for more details.
+*/
+
+#include "achievements.hpp"
+#include "gui/dialogs/modal_dialog.hpp"
+#include "gui/widgets/listbox.hpp"
+#include "gui/widgets/menu_button.hpp"
+
+#pragma once
+
+namespace gui2::dialogs
+{
+
+/**
+ * @ingroup GUIWindowDefinitionWML
+ *
+ * This shows a dialog displaying achievements.
+ *
+ * Key                       |Type           |Mandatory|Description
+ * --------------------------|-------------|---------|-----------
+ * selected_achievements_list|menu_button  |yes      |Allows selecting achievements by what content they're for.
+ * name                      |label        |yes      |The user displayed name of the achievement.
+ * description               |label        |yes      |The achievement's longer description.
+ * icon                      |image        |yes      |An icon to display to the left of the achievement.
+ */
+class achievements_dialog : public modal_dialog
+{
+public:
+	DEFINE_SIMPLE_EXECUTE_WRAPPER(achievements_dialog)
+
+	achievements_dialog();
+
+private:
+	achievements achieve_;
+	listbox* achievements_box_;
+	menu_button* content_names_;
+
+	void set_achievements_content();
+
+	virtual const std::string& window_id() const override;
+
+	virtual void pre_show(window& window) override;
+
+	virtual void post_show(window& window) override;
+};
+
+} // namespace gui2::dialogs
--- a/src/gui/dialogs/title_screen.cpp
+++ b/src/gui/dialogs/title_screen.cpp
@ -26,6 +26,7 @@
 #include "gui/auxiliary/find_widget.hpp"
 #include "gui/auxiliary/tips.hpp"
 #include "gui/core/timer.hpp"
+#include "gui/dialogs/achievements_dialog.hpp"
 #include "gui/dialogs/core_selection.hpp"
 #include "gui/dialogs/debug_clock.hpp"
 #include "gui/dialogs/game_version_dialog.hpp"
@ -163,6 +164,9 @@ void title_screen::init_callbacks()
 	register_hotkey(hotkey::TITLE_SCREEN__RELOAD_WML,
 		std::bind(&gui2::window::set_retval, std::ref(*this), RELOAD_GAME_DATA, true));

+	register_hotkey(hotkey::HOTKEY_ACHIEVEMENTS,
+		std::bind(&title_screen::show_achievements, this));
+
 	register_hotkey(hotkey::TITLE_SCREEN__TEST,
 		std::bind(&title_screen::hotkey_callback_select_tests, this));

@ -440,6 +444,12 @@ void title_screen::hotkey_callback_select_tests()
 	}
 }

+void title_screen::show_achievements()
+{
+	achievements_dialog ach;
+	ach.show();
+}
+
 void title_screen::button_callback_multiplayer()
 {
 	while(true) {
--- a/src/gui/dialogs/title_screen.hpp
+++ b/src/gui/dialogs/title_screen.hpp
@ -108,6 +108,8 @@ private:

 	void hotkey_callback_select_tests();

+	void show_achievements();
+
 	void button_callback_multiplayer();

 	void button_callback_cores();
--- a/src/hotkey/command_executor.cpp
+++ b/src/hotkey/command_executor.cpp
@ -16,6 +16,7 @@
 #include "hotkey/command_executor.hpp"
 #include "hotkey/hotkey_item.hpp"

+#include "gui/dialogs/achievements_dialog.hpp"
 #include "gui/dialogs/lua_interpreter.hpp"
 #include "gui/dialogs/message.hpp"
 #include "gui/dialogs/screenshot_notification.hpp"
@ -388,6 +389,12 @@ bool command_executor::do_execute_command(const hotkey_command&  cmd, int /*inde
 			preferences::toggle_minimap_draw_villages();
 			recalculate_minimap();
 			break;
+		case HOTKEY_ACHIEVEMENTS:
+			{
+				gui2::dialogs::achievements_dialog ach;
+				ach.show();
+			}
+			break;
 		default:
 			return false;
 	}
--- a/src/hotkey/hotkey_command.cpp
+++ b/src/hotkey/hotkey_command.cpp
@ -94,6 +94,7 @@ constexpr std::array<hotkey_command_temp, HOTKEY_NULL - 1> master_hotkey_list {{
 	{ HOTKEY_ZOOM_OUT, "zoomout", N_("Zoom Out"), false, scope_game | scope_editor, HKCAT_GENERAL, "" },
 	{ HOTKEY_ZOOM_DEFAULT, "zoomdefault", N_("Default Zoom"), false, scope_game | scope_editor, HKCAT_GENERAL, "" },
 	{ HOTKEY_FULLSCREEN, "fullscreen", N_("Toggle Full Screen"), false, scope_game | scope_editor | scope_main, HKCAT_GENERAL, "" },
+	{ HOTKEY_ACHIEVEMENTS, "achievements", N_("Achievements"), false, scope_game | scope_main, HKCAT_GENERAL, "" },
 	{ HOTKEY_SCREENSHOT, "screenshot", N_("Screenshot"), false, scope_game | scope_editor | scope_main, HKCAT_GENERAL, "" },
 	{ HOTKEY_MAP_SCREENSHOT, "mapscreenshot", N_("Map Screenshot"), false, scope_game | scope_editor, HKCAT_GENERAL, "" },
 	{ HOTKEY_ACCELERATED, "accelerated", N_("Toggle Accelerated Speed"), false, scope_game, HKCAT_GENERAL, "" },
--- a/src/hotkey/hotkey_command.hpp
+++ b/src/hotkey/hotkey_command.hpp
@ -96,6 +96,7 @@ enum HOTKEY_COMMAND {
 	HOTKEY_AI_FORMULA,
 	HOTKEY_CLEAR_MSG,
 	HOTKEY_LABEL_SETTINGS,
+	HOTKEY_ACHIEVEMENTS,

 	// Minimap
 	HOTKEY_MINIMAP_CODING_TERRAIN, HOTKEY_MINIMAP_CODING_UNIT,
--- a/src/hotkey/hotkey_handler.cpp
+++ b/src/hotkey/hotkey_handler.cpp
@ -336,6 +336,7 @@ bool play_controller::hotkey_handler::can_execute_command(const hotkey::hotkey_c
 	case hotkey::HOTKEY_SCROLL_DOWN:
 	case hotkey::HOTKEY_SCROLL_LEFT:
 	case hotkey::HOTKEY_SCROLL_RIGHT:
+	case hotkey::HOTKEY_ACHIEVEMENTS:
 		return true;

 	case hotkey::HOTKEY_SURRENDER: {
--- a/src/preferences/general.cpp
+++ b/src/preferences/general.cpp
@ -1026,5 +1026,41 @@ void set_addon_manager_saved_order_direction(sort_order::type value)
 	set("addon_manager_saved_order_direction", sort_order::get_string(value));
 }

+bool achievement(const std::string& content_for, const std::string& id)
+{
+	for(config& ach : prefs.child_range("achievements"))
+	{
+		if(ach["content_for"].str() == content_for)
+		{
+			std::vector<std::string> ids = utils::split(ach["ids"]);
+			return std::find(ids.begin(), ids.end(), id) != ids.end();
+		}
+	}
+	return false;
+}
+
+void set_achievement(const std::string& content_for, const std::string& id)
+{
+	for(config& ach : prefs.child_range("achievements"))
+	{
+		// if achievements already exist for this content and the achievement has not already been set, add it
+		if(ach["content_for"].str() == content_for)
+		{
+			std::vector<std::string> ids = utils::split(ach["ids"]);
+			if(std::find(ids.begin(), ids.end(), id) == ids.end())
+			{
+				ach["ids"] = ach["ids"].str() + "," + id;
+			}
+			return;
+		}
+	}
+
+	// else no achievements have been set for this content yet
+	config ach;
+	ach["content_for"] = content_for;
+	ach["ids"] = id;
+	prefs.add_child("achievements", ach);
+}
+

 } // end namespace preferences
--- a/src/preferences/general.hpp
+++ b/src/preferences/general.hpp
@ -277,4 +277,7 @@ namespace preferences {
 	sort_order::type addon_manager_saved_order_direction();
 	void set_addon_manager_saved_order_direction(sort_order::type value);

+	bool achievement(const std::string& content_for, const std::string& id);
+	void set_achievement(const std::string& content_for, const std::string& id);
+
 } // end namespace preferences
--- a/src/scripting/game_lua_kernel.cpp
+++ b/src/scripting/game_lua_kernel.cpp
@ -67,6 +67,7 @@
 #include "pathfind/pathfind.hpp"        // for full_cost_map, plain_route, etc
 #include "pathfind/teleport.hpp"        // for get_teleport_locations, etc
 #include "play_controller.hpp"          // for play_controller
+#include "preferences/general.hpp"
 #include "recall_list_manager.hpp"      // for recall_list_manager
 #include "replay.hpp"                   // for get_user_choice, etc
 #include "reports.hpp"                  // for register_generator, etc
@ -3064,6 +3065,102 @@ int game_lua_kernel::intf_play_sound(lua_State *L)
 	return 0;
 }

+/**
+ * Sets an achievement as being completed.
+ * - Arg 1: string - content_for.
+ * - Arg 2: string - id.
+ */
+int game_lua_kernel::intf_set_achievement(lua_State *L)
+{
+	const char *content_for = luaL_checkstring(L, 1);
+	const char *id = luaL_checkstring(L, 2);
+
+	for(achievement_group& group : game_config_manager::get()->get_achievements()) {
+		if(group.content_for_ == content_for) {
+			for(achievement& achieve : group.achievements_) {
+				if(achieve.id_ == id) {
+					// found the achievement - mark it as completed
+					preferences::set_achievement(content_for, id);
+					achieve.achieved_ = true;
+					return 0;
+				}
+			}
+			// achievement not found - existing achievement group but non-existing achievement id
+			ERR_LUA << "Achievement " << id << " not found for achievement group " << content_for;
+			return 0;
+		}
+	}
+
+	// achievement group not found
+	ERR_LUA << "Achievement group " << content_for << " not found";
+	return 0;
+}
+
+/**
+ * Returns whether an achievement has been completed.
+ * - Arg 1: string - content_for.
+ * - Arg 2: string - id.
+ * - Ret 1: boolean.
+ */
+int game_lua_kernel::intf_has_achievement(lua_State *L)
+{
+	const char *content_for = luaL_checkstring(L, 1);
+	const char *id = luaL_checkstring(L, 2);
+
+	if(resources::controller->is_networked_mp() && synced_context::is_synced()) {
+		ERR_LUA << "Returning false for whether a player has completed an achievement due to being networked multiplayer.";
+		lua_pushboolean(L, false);
+	} else {
+		lua_pushboolean(L, preferences::achievement(content_for, id));
+	}
+
+	return 1;
+}
+
+/**
+ * Returns information on a single achievement, or no data if the achievement is not found.
+ * - Arg 1: string - content_for.
+ * - Arg 2: string - id.
+ * - Ret 1: WML table returned by the function.
+ */
+int game_lua_kernel::intf_get_achievement(lua_State *L)
+{
+	const char *content_for = luaL_checkstring(L, 1);
+	const char *id = luaL_checkstring(L, 2);
+
+	config cfg;
+	for(const auto& group : game_config_manager::get()->get_achievements()) {
+		if(group.content_for_ == content_for) {
+			for(const auto& achieve : group.achievements_) {
+				if(achieve.id_ == id) {
+					// found the achievement - return it as a config
+					cfg["id"] = achieve.id_;
+					cfg["name"] = achieve.name_;
+					cfg["name_completed"] = achieve.name_completed_;
+					cfg["description"] = achieve.description_;
+					cfg["description_completed"] = achieve.description_completed_;
+					cfg["icon"] = achieve.icon_;
+					cfg["icon_completed"] = achieve.icon_completed_;
+					cfg["hidden"] = achieve.hidden_;
+					cfg["hidden_name"] = achieve.hidden_name_;
+					cfg["hidden_hint"] = achieve.hidden_hint_;
+					cfg["achieved"] = achieve.achieved_;
+					luaW_pushconfig(L, cfg);
+					return 1;
+				}
+			}
+			// return empty config - existing achievement group but non-existing achievement id
+			ERR_LUA << "Achievement " << id << " not found for achievement group " << content_for;
+			luaW_pushconfig(L, cfg);
+			return 1;
+		}
+	}
+	// return empty config - non-existing achievement group
+	ERR_LUA << "Achievement group " << content_for << " not found";
+	luaW_pushconfig(L, cfg);
+	return 1;
+}
+
 /**
 * Scrolls to given tile.
 * - Arg 1: location.
@ -4885,6 +4982,20 @@ game_lua_kernel::game_lua_kernel(game_state & gs, play_controller & pc, reports
 	lua_setfield(L, -2, "interface");
 	lua_pop(L, 1);

+	// Create the achievements module
+	cmd_log_ << "Adding achievements module...\n";
+	static luaL_Reg const achievement_callbacks[] {
+		{ "set", &dispatch<&game_lua_kernel::intf_set_achievement> },
+		{ "has", &dispatch<&game_lua_kernel::intf_has_achievement> },
+		{ "get", &dispatch<&game_lua_kernel::intf_get_achievement> },
+		{ nullptr, nullptr }
+	};
+	lua_getglobal(L, "wesnoth");
+	lua_newtable(L);
+	luaL_setfuncs(L, achievement_callbacks, 0);
+	lua_setfield(L, -2, "achievements");
+	lua_pop(L, 1);
+
 	// Create the audio module
 	cmd_log_ << "Adding audio module...\n";
 	static luaL_Reg const audio_callbacks[] {
--- a/src/scripting/game_lua_kernel.hpp
+++ b/src/scripting/game_lua_kernel.hpp
@ -119,6 +119,9 @@ class game_lua_kernel : public lua_kernel_base
 	int intf_heal_unit(lua_State *L);
 	int intf_message(lua_State *L);
 	int intf_play_sound(lua_State *L);
+	int intf_set_achievement(lua_State *L);
+	int intf_has_achievement(lua_State *L);
+	int intf_get_achievement(lua_State *L);
 	int intf_set_floating_label(lua_State* L, bool spawn);
 	int intf_remove_floating_label(lua_State* L);
 	int intf_move_floating_label(lua_State* L);
--- a/src/tests/gui/test_gui2.cpp
+++ b/src/tests/gui/test_gui2.cpp
@ -22,6 +22,7 @@
 #include "filesystem.hpp"
 #include "formula/debugger.hpp"
 #include "game_config.hpp"
+#include "game_config_manager.hpp"
 #include "game_config_view.hpp"
 #include "game_display.hpp"
 #include "game_events/manager.hpp"
@ -37,6 +38,7 @@
 #include "gui/dialogs/addon/install_dependencies.hpp"
 #include "gui/dialogs/addon/license_prompt.hpp"
 #include "gui/dialogs/addon/manager.hpp"
+#include "gui/dialogs/achievements_dialog.hpp"
 #include "gui/dialogs/attack_predictions.hpp"
 #include "gui/dialogs/campaign_difficulty.hpp"
 #include "gui/dialogs/campaign_selection.hpp"
@ -131,9 +133,12 @@ using namespace gui2::dialogs;

 struct test_gui2_fixture {
 	test_gui2_fixture()
+	: config_manager()
+	, dummy_args({"wesnoth", "--noaddons"})
 	{
 		/** The main config, which contains the entire WML tree. */
 		game_config_view game_config_view_ = game_config_view::wrap(main_config);
+		config_manager.reset(new game_config_manager(dummy_args));

 		game_config::config_cache& cache = game_config::config_cache::instance();

@ -152,6 +157,8 @@ struct test_gui2_fixture {
 	}
 	static config main_config;
 	static const std::string widgets_file;
+	std::unique_ptr<game_config_manager> config_manager;
+	std::vector<std::string> dummy_args;
 };
 config test_gui2_fixture::main_config;
 const std::string test_gui2_fixture::widgets_file = "widgets_tested.log";
@ -589,6 +596,10 @@ BOOST_AUTO_TEST_CASE(modal_dialog_test_wml_message_double)
 {
 	test<wml_message_double>();
 }
+BOOST_AUTO_TEST_CASE(modal_dialog_test_achievements_dialog)
+{
+	test<achievements_dialog>();
+}
 BOOST_AUTO_TEST_CASE(modeless_dialog_test_debug_clock)
 {
 	test_popup<debug_clock>();
--- a/utils/CI/schema_validation.sh
+++ b/utils/CI/schema_validation.sh
@ -33,6 +33,7 @@ validate() {

 validate_core() { validate "$1" ./wesnoth --validate data/_main.cfg; }
 validate_misc() { validate "$1" ./wesnoth --data-dir=. --validate=data/_main.cfg --preprocess-defines="$2"; }
+validate_achievements() { validate "Achievements" ./wesnoth --data-dir=. --validate=data/achievements.cfg --use-schema=data/schema/achievements.cfg; }
 validate_schema() { validate "$1" ./wesnoth --data-dir=. --validate-schema=data/schema/"$2".cfg; }

 validate_campaign() {
@ -75,11 +76,17 @@ validate_schema "Game Config"  "game_config"  || RET=1
 validate_schema "GUI2"         "gui"          || RET=1
 validate_schema "Server Pbl"   "pbl"          || RET=1
 validate_schema "WML Diff"     "diff"         || RET=1
+validate_schema "Achievements schema" "achievements" || RET=1
+
 validate_core "Core" || RET=1
-validate_misc "Editor"      "EDITOR" || RET=1
-validate_misc "Multiplayer" "MULTIPLAYER,MULTIPLAYER_A_NEW_LAND_LOAD" || RET=1
-validate_misc "Test"        "TEST"            || RET=1
+
+validate_achievements || RET=1
+
+validate_misc "Editor"         "EDITOR"                                  || RET=1
+validate_misc "Multiplayer"    "MULTIPLAYER,MULTIPLAYER_A_NEW_LAND_LOAD" || RET=1
+validate_misc "Test"           "TEST"                                    || RET=1
 validate_misc "World_Conquest" "MULTIPLAYER,LOAD_WC2,LOAD_WC2_EVEN_THOUGH_IT_NEEDS_A_NEW_MAINTAINER" || RET=1
+
 validate_campaign "Dead_Water"              "CAMPAIGN_DEAD_WATER"              "EASY" "NORMAL" "HARD" "NIGHTMARE" || RET=1
 validate_campaign "Delfadors_Memoirs"       "CAMPAIGN_DELFADORS_MEMOIRS"       "EASY" "NORMAL" "HARD"             || RET=1
 validate_campaign "Descent_Into_Darkness"   "CAMPAIGN_DESCENT"                 "EASY" "NORMAL" "HARD"             || RET=1
--- a/1
+++ b/1
@ -202,6 +202,7 @@
 9 test_store_unit_defense_deprecated
 0 special_note_from_movetype
 0 special_note_individual_unit
+0 has_achievement
 # Terrain mask tests
 0 test_terrain_mask_simple_nop
 0 test_terrain_mask_simple_set