diff --git a/addons/escoria-core/game/core-scripts/esc/commands/inventory_add.gd b/addons/escoria-core/game/core-scripts/esc/commands/inventory_add.gd
index 321fc1ba..6d274e53 100644
--- a/addons/escoria-core/game/core-scripts/esc/commands/inventory_add.gd
+++ b/addons/escoria-core/game/core-scripts/esc/commands/inventory_add.gd
@@ -13,6 +13,9 @@ extends ESCBaseCommand
 class_name InventoryAddCommand
 
 
+const ILLEGAL_STRINGS = ["/"]
+
+
 # Return the descriptor of the arguments of this command
 func configure() -> ESCCommandArgumentDescriptor:
 	return ESCCommandArgumentDescriptor.new(
@@ -27,13 +30,15 @@ func validate(arguments: Array):
 	if not .validate(arguments):
 		return false
 
-	if arguments[0].begins_with("i/"):
-		escoria.logger.error(
-			self,
-			"[%s]: invalid item name. Item name %s cannot start with 'i/'."
-					% [get_command_name(), arguments[0]]
-		)
-		return false
+	for s in ILLEGAL_STRINGS:
+		if s in arguments[0]:
+			escoria.logger.error(
+				self,
+				"[%s]: invalid item name. Item name %s cannot contain the string '%s'."
+						% [get_command_name(), arguments[0], s]
+			)
+			return false
+
 	return true
 
 
diff --git a/addons/escoria-core/game/core-scripts/esc/commands/inventory_remove.gd b/addons/escoria-core/game/core-scripts/esc/commands/inventory_remove.gd
index 8c11dc0c..55f04771 100644
--- a/addons/escoria-core/game/core-scripts/esc/commands/inventory_remove.gd
+++ b/addons/escoria-core/game/core-scripts/esc/commands/inventory_remove.gd
@@ -13,6 +13,9 @@ extends ESCBaseCommand
 class_name InventoryRemoveCommand
 
 
+const ILLEGAL_STRINGS = ["/"]
+
+
 # Return the descriptor of the arguments of this command
 func configure() -> ESCCommandArgumentDescriptor:
 	return ESCCommandArgumentDescriptor.new(
@@ -22,6 +25,23 @@ func configure() -> ESCCommandArgumentDescriptor:
 	)
 
 
+# Validate whether the given arguments match the command descriptor
+func validate(arguments: Array):
+	if not .validate(arguments):
+		return false
+
+	for s in ILLEGAL_STRINGS:
+		if s in arguments[0]:
+			escoria.logger.error(
+				self,
+				"[%s]: invalid item name. Item name %s cannot contain the string '%s'."
+						% [get_command_name(), arguments[0], s]
+			)
+			return false
+
+	return true
+
+
 # Run the command
 func run(command_params: Array) -> int:
 	escoria.inventory_manager.remove_item(command_params[0])
diff --git a/addons/escoria-core/game/core-scripts/esc/commands/set_global.gd b/addons/escoria-core/game/core-scripts/esc/commands/set_global.gd
index e7ecb191..88328b5f 100644
--- a/addons/escoria-core/game/core-scripts/esc/commands/set_global.gd
+++ b/addons/escoria-core/game/core-scripts/esc/commands/set_global.gd
@@ -16,6 +16,9 @@ extends ESCBaseCommand
 class_name SetGlobalCommand
 
 
+const ILLEGAL_STRINGS = ["/"]
+
+
 # Return the descriptor of the arguments of this command
 func configure() -> ESCCommandArgumentDescriptor:
 	return ESCCommandArgumentDescriptor.new(
@@ -25,6 +28,23 @@ func configure() -> ESCCommandArgumentDescriptor:
 	)
 
 
+# Validate whether the given arguments match the command descriptor
+func validate(arguments: Array):
+	if not .validate(arguments):
+		return false
+
+	for s in ILLEGAL_STRINGS:
+		if s in arguments[0]:
+			escoria.logger.error(
+				self,
+				"[%s]: invalid global variable. Global variable %s cannot contain the string '%s'."
+						% [get_command_name(), arguments[0], s]
+			)
+			return false
+
+	return true
+
+
 # Run the command
 func run(command_params: Array) -> int:
 	escoria.globals_manager.set_global(