1Spider Solitaire uses two full decks of cards (104 cards total), making it one of the few solitaire games that requires more than one standard 52-card deck.
2Spider Solitaire was named after the eight legs of a spider, corresponding to the eight foundation piles that must be completed to win the game.
3Spider gets harder with each suit you add, because a descending run of mixed suits cannot be moved as a group. No published study measures solvability per suit count, so treat any exact percentage you see with suspicion.
4Spider Solitaire became one of the most popular computer card games after Microsoft included it in Windows ME in 2000 and Windows XP in 2001.
5A Spider Solitaire game deals 54 cards across 10 tableau columns at the start, with the remaining 50 cards placed in 5 stock piles of 10 cards each.
6In Spider Solitaire, a completed sequence of 13 cards from King to Ace of the same suit is automatically removed from the tableau and placed on a foundation pile.
7Two-suit Spider is the usual step up for intermediate players: Spades and Hearts, 52 cards of each, so every stack you build has a one-in-two chance of being movable later.
