Q: If Play All is in effect, and there is a Bonus that adds 1 to Plays per turn, should we treat that as having the same effect as Play All +1?

…It has long been established that a Play Bonus will turn Play All But 1 into Play All. (Play All -1 +1 = Play All), so does the existence of Play All Plus 1 mean we should treat Play All with a +1 Play Bonus as Play All Plus 1?

For reference, the Rule: Play All Plus 1 was invented for Hundred Acre Wood Fluxx, and says: Play all of the cards in your hand, then take 1 card from the top of the Draw pile and play that as well. This immediately ends your turn.

A: No. The previous ruling still stands that if Play All is in effect, adding a Bonus to your number of Plays per turn does nothing – you simply still Play All. Think of the +1 in Play All +1 as tacking a mandatory Mystery Play on to the end of a regular Play All. That extra +1 played isn’t really the same as your other card plays from your hand because it’s completely random, so we don’t think it should be treated strictly mathematically as when adding a Play Bonus to Play All But 1.

Note that this also means that if Play All Plus 1 were in effect and you had a Bonus which added to your Play count, you would still simply Play All… then tack on the 1 mandatory draw & play from the top of the deck. So neither Play All nor Play All Plus 1 is affected by Play Bonuses.

For reference: Rules that add to your Play count:
Child Bonus: Optional. Extra 1 Play for anyone 12 or younger, or the youngest player if none are 12 or under.
Rich Bonus: Mandatory. The player with the most Keepers Plays 1 extra.
Christmas Bonus: Mandatory. If it is Christmas Day, all players add 1 to their Draw & Play. Otherwise only the player with Santa in play does so.
Martian Technology: Mandatory. Any player with a piece of Martian Technology in play adds 1 to their Draw & play.
Monster Bonus: Mandatory. Any player with a Monster in play adds 1 to their Draw & Play.
Fear of the Unknown: Optional to reveal a fear and get to Draw and Play 1 extra on your turn.
[certain Keeper] Bonus: Mandatory. If a certain Keeper is in play, all players add 1 to both their Draw & Play count.
        Party Bonus (if the Party is in play anywhere)
        Love Bonus (if Love is in play anywhere)
        Miskatonic Study Group (if the Necronomicon is in play anywhere)
        Bacchus Bonus (if Bacchus/Dionysius is in play anywhere)