How is bid whist different from classic partnership whist?

Bid whist differs significantly from classic partnership whist in its mechanics, complexity, and use of specialized equipment.12

• Deck and Setup: While classic whist uses a standard 52-card deck, bid whist typically uses a 54-card pack that includes two jokers ("big" and "little"). Additionally, bid whist utilizes a "kitty"—six cards dealt facedown that the winning bidder takes into their hand—whereas classic whist deals all cards directly to the players.12
• Bidding: In classic whist, the trump suit is traditionally determined by turning up the last card dealt. In contrast, bid whist features a competitive bidding process where players bid on the number of tricks ("books") they intend to win and specify whether the game will be played "uptown" (high), "downtown" (low), or at no-trump.21
• Card Ranking: Bid whist features variable card rankings depending on the bid; in "uptown" bids, cards rank from Ace down to 2, while in "downtown" bids, they rank from Ace up to King.1
• Scoring: Scoring in bid whist is based on fulfilling a contract; declarers score points for tricks made above six, but lose points if they fail to meet their bid.1