N        This condition can be used to check if a client with the given ID exists on the server or not.

It takes only one parameter, the client ID (0 to 65534, inclusive).


This condition will only create an error if you pass an invalid client ID (-1 or less, 65535 or more). If the client ID is not found, or other issues, such as the server not hosting, it will simply return false.


IDs are assigned on connect – step 2 of the Lacewing handshake – on a lowest available basis, and never changed; so if three clients connect, and the second client to connect disconnects, there will be 2 clients but with IDs 0 and 2, not 0 and 1.


In a Connection > On disconnect event, the disconnecting peer is considered to NOT exist by this condition. This is because it is removed from the server's main client list so the Client > Number of clients on the server expression excludes it during a disconnect event.

Note that the client ID itself is not freed for re-use until the disconnect event finishes.


This condition does not change the currently selected client.