diff --git a/core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/annotations/RDDeprecated.kt b/core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/annotations/RDDeprecated.kt
new file mode 100644
index 0000000..c29131b
--- /dev/null
+++ b/core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/annotations/RDDeprecated.kt
@@ -0,0 +1,19 @@
+package cn.rdlevel.rdkt.core.annotations
+
+/**
+ * This annotation marks APIs that are not recommended for use in levels, either because they are broken, or there are better alternatives available. Use with caution.
+ */
+@MustBeDocumented
+@Target(
+    AnnotationTarget.CLASS,
+    AnnotationTarget.FUNCTION,
+    AnnotationTarget.PROPERTY,
+    AnnotationTarget.TYPEALIAS,
+    AnnotationTarget.CONSTRUCTOR,
+)
+@Retention(AnnotationRetention.BINARY)
+@RequiresOptIn(
+    "This API is not recommended for use in levels, either because it is broken, or there are better alternatives available. Use with caution.",
+    RequiresOptIn.Level.WARNING,
+)
+public annotation class RDDeprecated
\ No newline at end of file
diff --git a/core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/settings/CustomClasses.kt b/core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/settings/CustomClasses.kt
index abd51db..0f27452 100644
--- a/core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/settings/CustomClasses.kt
+++ b/core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/settings/CustomClasses.kt
@@ -1,5 +1,6 @@
 package cn.rdlevel.rdkt.core.settings
 
+import cn.rdlevel.rdkt.core.annotations.RDDeprecated
 import cn.rdlevel.rdkt.core.settings.CustomClasses.INJURY
 
 
@@ -56,6 +57,6 @@ public object CustomClasses {
      * Replaces hearts with pumpkins.
      * Currently, this is broken and does not work.
      */
-    @Deprecated("This custom class is currently broken and does not work.")
+    @RDDeprecated
     public const val HALLOWEEN: String = "Halloween"
 }
\ No newline at end of file