A: If Double Vision is in play with Draw 1, making players Draw 2 instead, and then someone plays Draw 2, the draw rule has gone from “Draw 2” to “Draw 2” so no additional cards should be drawn.
Here is another example: when going from Draw 1 + Double Vision (= Draw 2) to Draw 4, the player has already drawn 2 on their turn, and would need to draw 2 more to make their total drawn 4.
A: We’d consider any cards which change the meaning of numerals on a card to be mutually exclusive to each other. Only one of them can be in play at a time, so if one is out, and someone plays a different one, the previous one would be discarded.
Inflation (Fluxx 5.0)(also available as a promo card)
Double Vision (Fluxx Remixx, Drinking Fluxx, More Rules promo pack)
One, Two, Five! (Monty Python Fluxx)
Increment All (Math Fluxx)
Mathematical! (Adventure Time Fluxx)
Note that you’ll find almost all of these (except for 1,2,5) on the same line in the Fluxx card comparison spreadsheet, since we consider these to be kind of variations on Inflation.
A: Yes. Since everything happens instantly in Fluxx, Draw 3 Play 2 Of Them (D3P2) suddenly becomes Draw 4 Play 3 Of Them (D4P3, if you will). The player should immediately draw an extra card and add it to the remainder of the cards being chosen from (the mini hand for the Action, not the set-aside main hand). It’s kind of like if you’d only drawn 2 cards instead of the 3 you were supposed to, realizing the mistake after playing one of them, and drawing the extra card you need at that point.
Of course, your regular hand will also need an extra card, since the Draw Rule itself has also incremented. You could do that at the time you’re executing your D3P2 by drawing a card and adding it to your set-aside hand, or you could catch up with that when you pick your regular hand back up again after the action. Note you’ll also have an extra Play to execute as well.
Star Trek Fluxx includes Fizzbin, which is similar to D3P2/D2UE. If Inflation was played as part of Fizzbin, all numbers would need to be increased, so you’d draw an extra card from the draw pile, and take an extra card from your neighbor. You should then reshuffle your temporary Fizzbin hand and continue.
Adventure Time includes the Inflation analogue, Mathematical! Inflation is also available as a promo card to add to any Fluxx deck.
Math Fluxx includes a card called Increment All, which is similar to Inflation except it only affects Actions and New Rules.
Drinking Fluxx includes a card called Double Vision, which is similar to Inflation, but only changes 1 to 2, without affecting any higher numbers, so actually, it won’t affect Draw 3 Play 2, but it’s worth noting.