The rules of Fluxx are constantly in.. well.. flux.
A third type of card in the game are Rule cards, which alter the rules of the game as it is being played. Usually, a rule card adds to the rules that are currently in the game. The only exception to this is if a current rule is in conflict with a new rule.
As an example, at the start of the game the basic rules are "Draw 1, Play 1". If you play the "Play 3" rule, the rules of the game are now "Draw 1, Play 3". If you play the "Draw 2" rule, the rules of the game would become "Draw 2, Play 3". If someone played the "Play All" rule, this conflicts with the "Play 3" rule, so it would be discarded and the rules of the game would be "Draw 2, Play All". Clear as mud?
Rules take effect immediately. So for example:
- You start your turn by drawing one card.
- You play the "Draw 2" Rule.
- You are now in violation of the rules, because you only drew 1 card. So, you must draw one more.
The last type of cards are the blue action cards, which add even more chaos to the game. They may allow you to take another turn, change the other of play in the game, steal a keeper from someone, change hands with another player, and so on.
In all, there is a lot of chaos and change in Fluxx. You never know what's going to happen next. You may even be forced to play a card that allows another player to win the game. It's short and fast and good filler, and we like it even if a lot of other people don't. In fact, we like it for the same reasons that other people hate it. Go figure.
If you like Fluxx, you can also get "Fluxx Blankx", which gives you some blank cards to allow you to make up your own rules and goals to the game and give it a custom feel.