All aspects of the game can be changed by any player at any time, including the conditions for winning the game, called Goals. This ever-changing nature of the rules gives the game its name “Fluxx" (from “flux," which means “change" or “fluctuation").
Each player gets 3 cards to start. First player to play is determined by whoever calls it, or whoever draws a card from the deck first—meaning it doesn’t really matter.
There are 5 types of Fluxx cards: New Rules, Goals, Keepers, Actions, and Creepers. At the start of play, the card Basic Rules is placed in the middle of the play area. The Basic Rules are simple: on your turn, draw one card and play one card.
New Rule cards, as their name states, change the rules of the game. They can change the number of cards drawn per turn, number of cards that can be played, and the rules that affect the other cards: Goal, Keeper, and Creeper cards. They can also place limits (or remove them) on hand size and number of Keepers. New Rules that modify the Basic Rules are placed on top of the Basic Rules card. New Rules that contradict a New Rule in play cause the older New Rule to be discarded. Deft manipulation of the rules is the difference between winning and losing.
Keeper cards are played right in front of a player face up, and kept there (at least until someone plays a card that steals it or removes it from play). The Keeper cards are represented by items such as “Cheese," or concepts such as “Love." Keepers are usually needed to fulfill the conditions defined in Goal cards.
Goal cards contain the conditions needed for winning the game. Once a Goal is in play, any player who fulfills the conditions will win the game. There can only be one Goal in play at a time (unless a special Rule is played), so the most recently played Goal will cause the previous Goal to be discarded.
Action cards are played and then discarded. Sometimes they just cause mayhem, but usually they are a part of a winning strategy.
Creeper cards are undesirable cards that usually prevent you from winning. Creepers are immediately played in front of you when you draw them, and act like “negative" Keepers that are hard to get rid of.