When do scripts only run on client.

[Mr.Peanut]

Under what circumstances does a script only run on a client?  I am trying to think of situations where this might occur.  If I: car AddAction["Fart","fart.sqs"] and a player actions Fart, will fart.sqs be run on all clients?

[Artak]

Scripts will run on all clients if they're launched from global space. There are exceptions like some eventhandlers and infact action is one of them.
An when a script is executed with an action, the script will run on only that clients computer who used the action.

If player actions Fart, fart.sqs will not be run on all clients.