The aim of Spider is to make 8 descending sequences of cards, in suit, starting with the King and going down in rank to Ace. It is played with two packs of cards, and at three levels of difficulty: one suit (easiest), two suits, and all four suits (hardest).
The game starts with 54 cards dealt into 10 piles forming the tableau with only the top card of each pile face up (it is possible to vary which cards are dealt face up). The remaining cards are placed in the stock. There are 8 foundation piles at the top of the table.
In Spider, you build sequences of cards down in rank. You may move any card onto another of 1 rank higher regardless of suit. However, you may only move sequences with matched suit unless you have changed this in the customization options. Clicking the stock will cause an additional card to be dealt onto each of the tableau piles. Cards on the tableau may be turned face-up once uncovered. If you succeed in building a qualifying sequence from King to Ace, those cards can be placed on a foundation pile.
With strict rules of Spider you can't deal a new row of cards if any of the tableau piles are empty. However, you can turn this off in the options. Also, you can choose what cards may be placed in empty tableau piles.
Spider is won when you have moved all the cards from the tableau to the foundations. If you run out of moves before winning, the game is over.