In Star Fluxx, some Keepers give you abilities that don't take up an action. Are Keeper abilities in Star Fluxx available immediately after the Keeper is put on the table, on the next turn, or just the next time you have an action available?
This is the answer from Loney Labs (Alison Looney)
We would rule that you can use the power of a Keeper as soon as you play it. There's no way it would depend upon keeper or hand limits, or play rules. Your turn is not over until you have taken all optional extra actions, including those based on special Keeper powers and extra actions on Rules. So, as soon as you play that Keeper (or that Rule) you can do what it says you can do, because your turn is not over until you have taken (or decided not to take) that optional extra action.
It may happen that a Keeper power has no effect at a given time. Example: in Star Fluxx, you could steal a crew member with the Captain as soon as you play the Captain - but if no other players have crew members on the table to steal, then that's not going to be an option. Another example: In Zombie Fluxx you could kill a Zombie with your Shotgun as soon as you play the Shotgun, but if there are no Zombies to kill, obviously nothing's going to happen.
All keeper actions can be triggered from the moment they enter play (unless otherwise stated).
However, if that keeper is your final play, your turn immediately ends and you will not be able to trigger any ability that requires it to be your turn.
Watch your play order and you can pop anything the turn it comes out.