Spades Scorekeeper allows users to keep score for the classic card game of Spades. Because many groups have varying "House Rules", Spades Scorekeeper allows users to specify the following optional rules: 1. Is zero a valid bid? 2. Do overtricks carry over? 3. Do overtricks count if Double Nil is failed? 4. Is a 200+ lead required to bid Blind Nil? 5. Can both players bid Blind Nil? Spades Scorekeeper also attempts to detect invalid hands (forgetting to enter bids and/or not taking all 13 tricks)