Uno Variation: Three Piles
Requirements: 1 or more Uno decks (any variety)
Time: ~5-10 min/round
When starting the game, create three discard piles instead of one. If "Starting Neutral" is not in effect, the starting player is only affected by the first card that is flipped over to create a discard pile.
Each discard pile acts independently of the others, but no pile can be played on twice in a row. If a Stacking rule is being used, cards can still be stacked, but to do so, the stacked card must be played on a different pile, not on the card it is being stacked on. For example, if a Draw 2 card is played on Pile A, the next player may play another Draw 2 card, but must be able to do so on Pile B or C to stack the effect.
This is a very simple variation to implement, but still has the benefit of completely changing the nature and strategy of the game. Because each player has two piles to play on at any time, the games tend to be shorter and more fast paced.
Although fast paced games can be fun, this variation makes it much more likely that a game will end without a player drawing any cards or ever being unable to play a card on her turn.
The simplicity of this variation makes it fun to try as well as to experiment with. If you find a way to improve on these rules, let us know.