In our last game, the "play all but one" rule was into play . But also a rule (dutch fluxx) that said the one with the most keepers can play one more card.
Does this mean he can play all his cards, or should he still keep one left in his hands? (Translated into English the dutch card reads: Save one card in your hand and play all the rest.)
Since the dutch fluxx card says "the one with the most keepers can play one more card" (as opposed to must play one more card) then it would be that player's choice if they want to play the last card or not.
The key is in the compulsion, since "can" is not compulsory. It is possible that the wording in dutch has different compulsory connotations, but based on the English translation, I can only conclude that it is not required.
Sounds like you have your own answer ready. The rules for Fluxx tend to stack. You're absolutely right, that one person has to play all of his/her cards.
If the player in question has 6 cards on hand and 'play 5' is on the table, as well as the Jet-Set Bonus, does he get to play all his cards? This question is not really different from yours.
