<cat>Code.Entity</cat> <title>Entity Tags</title> Entities can be tagged with string tags. These tags are networked, so are also available for query on the client. ⤶ Entity tags are (in most cases) automatically propagated to all [physics shapes](https://asset.party/api/Sandbox.PhysicsShape) of the entity, which are then used for determine which shapes should collide with each other.⤶ ⤶ Game developers can then set up which tags collide with each other in the games' project settings.⤶ ⤶ <upload src="70c/8dac70d7ed26611.png" size="81491" name="image.png" />⤶ ⤶ ⤶ # Setting Tags ``` // set one tag on the entity player_entity.Tags.Add( "player" ); // set multiple tags on the entity enemy_entity.Tags.Add( "enemy", "threat" ); // updating tags programmatically (adds if true, removes if false) door_entity.Tags.Set( "locked", IsLocked() ); // removing tags enemy_entity.Tags.Remove( "threat" ); ``` # Querying Tags ``` if ( enemy.Tags.Has( "threat" ) ) { // run away } ``` # Using in Traces ``` // Only hit entities with the world tag tr = Trace.Ray( startpos, endpos ) .WithTag( "world" ) .Run(); // Hit enemies that are a threat tr = Trace.Ray( startpos, endpos ) .WithAllTags( "enemy", "threat" ) .Run(); // Hit enemies or players tr = Trace.Ray( startpos, endpos ) .WithAnyTags( "enemy", "player" ) .Run(); // Hit anything but players tr = Trace.Ray( startpos, endpos ) .WithoutTags( "player" ) .Run(); // Hit anything but players and world tr = Trace.Ray( startpos, endpos ) .WithoutTags( "player", "world" ) .Run(); ``` # Detecting Tag Changes ``` protected override void OnTagAdded( string tag ) { } protected override void OnTagRemoved( string tag ) { } ```