WHEN PLAYER NUM
From 3DGE Wiki
Usage:
WHEN_PLAYER_NUM <minimum players> [maximum players]
Description:
Use this to define how many COOP or DM players have to be in a game for this trigger to exist. Useful for splitscreen multiplayer and/or bots.
Details:
<minimum players> gives the minimum number of players.
[maximum players] gives the maximum number of players, with no limit when this value is absent.
Valid numbers are 1 to 16, since 3DGE can handle up to 16 players.
See Also:
Use WHEN_APPEAR to define what game modes (like DeathMatch) the script appears in.