Spit

When both players are ready they take the top cards from their deck and place them face up in the middle of the table, next to each other. This forms two discard piles. The players are then supposed to put as many cards as they can, as fast as they can on top of the discard piles. Both players can put cards onto both piles, the piles don't belong to a particular player. When you put a card on a discard pile it must be either one higher or one lower than the top card on the pile. E.g. you can put a 5 or a 7 on a 6. Aces are high and low, so you could put Q K A 2 3 2 A K etc. There are a few moves you can make:

Take a faceup card from one of your stacks and put it on a discard pile if it's one higher or one lower than the card at the top of the pile.
If you've taken the top card of one of your stacks and played it, you can flip the card below so it's turned face up.
Combine faceup cards in your stacks if they have the same rank. E.g. if stacks 1 and 2 both have a 5 as the top card you can take the 5 from stack 2 and put it on top of the 5 on stack 1 and then flip the next card on stack 2. This allows you to open more of your cards which you can then try to play onto the discard piles.
If one of your stacks is completely empty you can move one of the top cards on one of your other stacks onto it and then flip the top card of that stack up. Again, this opens up more of your cards, helping you to get rid of them faster.
During this part of the game the important thing is to play as fast as you can, move cards around to open up as many of your cards as you can and get rid of them. At some point both players will be stuck and can't make any more moves. When that happens the game will tell you to click on your deck, and then both you and the computer players will move one card from the top of your decks onto the discard piles. As soon as the new cards are there you can go back to getting rid of your cards as fast as you can until you're both stuck again or one of you has finished all his stacks.

When one player has finished all the cards in his stacks the round is finished. Then the player who finished first picks one of the discard piles and the other player gets the other pile. You should always pick the smaller pile, but it can sometimes be hard to see which one is smaller if they have roughly the same number of cards, and you can't count the cards. Now the players add the cards in their pile to their decks and create 5 new stacks, the same way as in the beginning. The important part is that the discard piles are not shuffled. Now, the cards in the discard piles are already ordered, so the new stacks will have pretty well ordered cards which makes the game even more intense and lets you get rid of your cards even faster!

This continues until at some point a player gets a discard pile that is so small that he can't make 5 full stacks, and won't have any deck. He then creates as much of the stacks as he can, but since he has no deck there will now only be one discard pile on the table. The game continues as usual, except with only one discard pile, and if the player who didn't have any deck gets rid of all his cards first then he has won the whole game. I.e. if you end up with no cards in your stacks, no deck, and there's only one discard pile on the table then you've won!