The contract determines the type of the game (trumps or no-trumps) and the contract level.

The contract level determines the number of tricks the declaring side has to win in the card play.

There are 7 levels of the contract. The first 6 out of 13 tricks (lower half) are called the "book". To determine the number of tricks required to fulfill the contract, you add 6 to the level of the contract. The 1^st level is the lowest and the declaring side commits to win 7 tricks (6+1), the 7^th level is the highest and the declaring side must win all 13 tricks (6+7).

Players offer contracts one after another; we call it making a "bid". To offer a contract, players have to bid a higher contract than the previous one. For this purpose, suits are ranked with clubs ♣ as lowest, diamonds ♦, hearts ♥, spades ♠, and the No-Trump contract is the highest on all levels.

♣ and ♦ are called minor suits
♥ and ♠ are called Major suits

The bidding ends when 3 players pass. Exception: in the first round of the bidding, each player has the right to make a bid. The last bid becomes the final contract.

The player of the partnership who offered the type of contract (trumps, NT) first becomes the "declarer", his partner is the "dummy". The opponents are called "defenders".