declarer's vulnerability. Overtrick points When declarer makes overtricks, their score value depends upon the contract denomination, declarer's vulnerability and whether or not the contract is undoubled, doubled or redoubled. In an undoubled contract each overtrick earns the same as in contract points (30 for notrump and major suit contracts, 20 for minor suit contracts); values increase significantly when the contract has been doubled or redoubled, especially when vulnerable. Slam bonus Bonuses are awarded for all contracts bid and made: a small slam, or successful contract to win 12 of 13 tricks, earns a bonus of 500 points if not vulnerable and 750 points if vulnerable; a grand slam, or successful contract to win all 13 tricks, earns a bonus of 1000 points if not vulnerable and 1500 points if vulnerable. Doubled or redoubled bonus When a doubled or redoubled contract is made, a bonus is awarded to the declaring side. It is colloquially referred to as a bonus for "insult", meaning that the opponents have insulted the pair by suggesting that the declarer will not make the contract. 50 points are awarded for a doubled contract made, and 100 points are awarded for a redoubled contract made. In scoring notation, a doubled contract is indicated by an 'X" after the contract (e.g. a contract of four hearts doubled is indicated by 4 X); a redoubled contract is indicated by "XX" (e.g. 4 XX). Penalty points When a contract is defeated, penalty points are awarded to the defending side. The value of the penalty depends on the number of undertricks, whether the declaring side is vulnerable or not vulnerable and whether the contract was undoubled, doubled or redoubled. Without a double or redouble, every undertrick has a fixed cost of 100 or 50 points. The scores for (re)doubled undertricks are such that after the first vulnerable undertrick, n vulnerable undertricks cost the same as n+1 undertricks when not vulnerable; for example, four undertricks when doubled and not vulnerable cost 800 points (100+200+200+300), the same as three undertricks when doubled and vulnerable (200+300+300). Rubber bonus In rubber bridge only, a bonus is awarded at the conclusion of the rubber as follows: for a completed rubber, the side which wins the rubber, i.e. is first to win two games, receives a rubber bonus: if the opponents have won no games, i.e. they are not vulnerable, the rubber bonus is 700 points; colloquially known