ismob

ismob <creature>

Whether a creature is an NPC (a mobile) rather than a player.

Arguments

<creature> — the creature to test. A null value or a non-creature yields false.

A bool — true if the creature is an NPC, false if it is a player (or the argument does not resolve to a live creature).

after command (say) {
  do "say ismob self=[ismob $self]."
}

The owner $self is a mobile, so [ismob $self] is true.

before command (enter) {
  require [ismob $actor]
  do "say Only mobiles may pass."
}

This guard lets the handler run only when the actor is an NPC; for a player actor the script advances to the next matching handler (see require).