diff --git a/simulation/definitions/SimulationDefinitions.gd b/simulation/definitions/SimulationDefinitions.gd
index 1198bda..7c0f613 100644
--- a/simulation/definitions/SimulationDefinitions.gd
+++ b/simulation/definitions/SimulationDefinitions.gd
@@ -21,54 +21,77 @@ const PROFESSION_PATHS := [
 	"res://simulation/definitions/professions/wanderer.tres"
 ]
 
+static var _action_list: Array[ActionDefinition] = []
+static var _profession_list: Array[ProfessionDefinition] = []
+static var _action_map: Dictionary = {}
+static var _profession_map: Dictionary = {}
+static var _profession_id_list: Array[StringName] = []
+static var _cache_valid := false
+
+
+static func _ensure_cache() -> void:
+	if _cache_valid:
+		return
+	_action_list = []
+	_profession_list = []
+	_action_map = {}
+	_profession_map = {}
+	_profession_id_list = []
 
-static func get_actions() -> Array[ActionDefinition]:
-	var definitions: Array[ActionDefinition] = []
 	for path in ACTION_PATHS:
 		var definition := load(path) as ActionDefinition
 		if definition != null:
-			definitions.append(definition)
-	return definitions
+			_action_list.append(definition)
+			_action_map[definition.action_id] = definition
 
-
-static func get_professions() -> Array[ProfessionDefinition]:
-	var definitions: Array[ProfessionDefinition] = []
 	for path in PROFESSION_PATHS:
 		var definition := load(path) as ProfessionDefinition
 		if definition != null:
-			definitions.append(definition)
-	return definitions
+			_profession_list.append(definition)
+			_profession_map[definition.profession_id] = definition
+			_profession_id_list.append(definition.profession_id)
+
+	_cache_valid = true
+
+
+static func invalidate_cache() -> void:
+	_cache_valid = false
+
+
+static func get_actions() -> Array[ActionDefinition]:
+	_ensure_cache()
+	return _action_list
+
+
+static func get_professions() -> Array[ProfessionDefinition]:
+	_ensure_cache()
+	return _profession_list
 
 
 static func get_action(action_id: StringName) -> ActionDefinition:
-	for definition in get_actions():
-		if definition.action_id == action_id:
-			return definition
-	return null
+	_ensure_cache()
+	return _action_map.get(action_id)
 
 
 static func get_profession(profession_id: StringName) -> ProfessionDefinition:
-	for definition in get_professions():
-		if definition.profession_id == profession_id:
-			return definition
-	return null
+	_ensure_cache()
+	return _profession_map.get(profession_id)
 
 
 static func get_profession_ids() -> Array[StringName]:
-	var ids: Array[StringName] = []
-	for definition in get_professions():
-		ids.append(definition.profession_id)
-	return ids
+	_ensure_cache()
+	return _profession_id_list
 
 
 static func validate() -> Array[String]:
+	_ensure_cache()
 	var errors: Array[String] = []
-	if get_actions().size() != ACTION_PATHS.size():
+	if _action_list.size() != ACTION_PATHS.size():
 		errors.append("One or more ActionDefinition resources failed to load")
-	if get_professions().size() != PROFESSION_PATHS.size():
+	if _profession_list.size() != PROFESSION_PATHS.size():
 		errors.append("One or more ProfessionDefinition resources failed to load")
 	var action_ids := {}
-	for definition in get_actions():
+	for definition in _action_list:
 		for error in definition.validate():
 			errors.append("ActionDefinition: " + error)
 		if action_ids.has(definition.action_id):
@@ -76,14 +99,14 @@ static func validate() -> Array[String]:
 		action_ids[definition.action_id] = true
 
 	var profession_ids := {}
-	for definition in get_professions():
+	for definition in _profession_list:
 		for error in definition.validate():
 			errors.append("ProfessionDefinition: " + error)
 		if profession_ids.has(definition.profession_id):
 			errors.append("Duplicate profession_id '%s'" % definition.profession_id)
 		profession_ids[definition.profession_id] = true
 
-	for definition in get_actions():
+	for definition in _action_list:
 		if (
 			not definition.preferred_profession_id.is_empty()
 			and not profession_ids.has(definition.preferred_profession_id)