diff --git a/OpenRA.Mods.Common/UpdateRules/Rules/20210321/UnhardcodeBaseBuilderBotModule.cs b/OpenRA.Mods.Common/UpdateRules/Rules/20210321/UnhardcodeBaseBuilderBotModule.cs
index ccbb86e44d..adf8f6c9c6 100644
--- a/OpenRA.Mods.Common/UpdateRules/Rules/20210321/UnhardcodeBaseBuilderBotModule.cs
+++ b/OpenRA.Mods.Common/UpdateRules/Rules/20210321/UnhardcodeBaseBuilderBotModule.cs
@@ -16,7 +16,7 @@ namespace OpenRA.Mods.Common.UpdateRules.Rules
 {
 	public class UnhardcodeBaseBuilderBotModule : UpdateRule, IBeforeUpdateActors
 	{
-		MiniYamlNodeBuilder defences;
+		MiniYamlNodeBuilder defenses;
 
 		// Excludes AttackBomber and AttackTDGunboatTurreted as actors with these AttackBase traits aren't supposed to be controlled.
 		readonly string[] attackBase =
@@ -43,7 +43,7 @@ namespace OpenRA.Mods.Common.UpdateRules.Rules
 
 		public IEnumerable<string> BeforeUpdateActors(ModData modData, List<MiniYamlNodeBuilder> resolvedActors)
 		{
-			var defences = new List<string>();
+			var defenses = new List<string>();
 
 			foreach (var actor in resolvedActors)
 			{
@@ -78,12 +78,12 @@ namespace OpenRA.Mods.Common.UpdateRules.Rules
 				if (isBuildable && isBuilding && canAttack)
 				{
 					var name = actor.Key.ToLowerInvariant();
-					if (!defences.Contains(name))
-						defences.Add(name);
+					if (!defenses.Contains(name))
+						defenses.Add(name);
 				}
 			}
 
-			this.defences = new MiniYamlNodeBuilder("DefenseTypes", FieldSaver.FormatValue(defences));
+			this.defenses = new MiniYamlNodeBuilder("DefenseTypes", FieldSaver.FormatValue(defenses));
 
 			yield break;
 		}
@@ -100,9 +100,9 @@ namespace OpenRA.Mods.Common.UpdateRules.Rules
 		{
 			foreach (var squadManager in actorNode.ChildrenMatching("BaseBuilderBotModule", includeRemovals: false))
 			{
-				if (!squadManager.ChildrenMatching(defences.Key, includeRemovals: false).Any())
+				if (!squadManager.ChildrenMatching(defenses.Key, includeRemovals: false).Any())
 				{
-					squadManager.AddNode(defences);
+					squadManager.AddNode(defenses);
 					anyAdded = true;
 				}
 			}
diff --git a/mods/ra/languages/lua/en.ftl b/mods/ra/languages/lua/en.ftl
index db744178f5..4a4e81ccc1 100644
--- a/mods/ra/languages/lua/en.ftl
+++ b/mods/ra/languages/lua/en.ftl
@@ -267,7 +267,7 @@ flame-turret-deactivated = Flame Turret deactivated.
 console = Console
 sarin-dispenser-activated = Sarin Nerve Gas dispensers activated.
 tesla-coil-deactivated = Tesla Coil deactivated.
-tesla-coil-activated = Initialising Tesla Coil defence.
+tesla-coil-activated = Initialising Tesla Coil defense.
 prisoners-escaping = Warning, prisoners are attempting to escape!
 intercom = Intercom
 hurry-base-compromised = The base is compromised. We have to hurry the execution!
diff --git a/mods/ra/maps/intervention/rules.yaml b/mods/ra/maps/intervention/rules.yaml
index b2791d8a06..d26164ee11 100644
--- a/mods/ra/maps/intervention/rules.yaml
+++ b/mods/ra/maps/intervention/rules.yaml
@@ -6,7 +6,7 @@ World:
 	LuaScript:
 		Scripts: campaign.lua, utils.lua, intervention.lua
 	MissionData:
-		Briefing: The Soviet Air Force is flying air raids against a civilian village.\n\nWe have to do everything in our power to stop them!\n\nYour job is to establish a base on the mainland ASAP. We can prevent the village's destruction by capturing the enemy's Air Force Headquarters building. The enemy base is heavily guarded, though.  You will not have enough time to build a force big enough to overpower the Soviet defences. You will have to find a way to sneak in!\n\nGood luck, Commander!\n
+		Briefing: The Soviet Air Force is flying air raids against a civilian village.\n\nWe have to do everything in our power to stop them!\n\nYour job is to establish a base on the mainland ASAP. We can prevent the village's destruction by capturing the enemy's Air Force Headquarters building. The enemy base is heavily guarded, though.  You will not have enough time to build a force big enough to overpower the Soviet defenses. You will have to find a way to sneak in!\n\nGood luck, Commander!\n
 	ScriptLobbyDropdown@difficulty:
 		ID: difficulty
 		Label: dropdown-difficulty.label