Polish Club (Polish: Wspólny Język, literally "Common Language") is a bridge bidding system which was developed in Poland, where it is the most popular bidding system, and which is also used by players of other countries.
Gambling (no stopper outside) Strong, semi−solid suit, slam interest Invites to game after an initial one-over-one response.
After trump agreement, an unusual jump shift at the 5-level (or 4♠ when hearts are agreed) asks for key cards, exclusive of the ace of the bid suit.
The cheapest bid after key cards are shown asks for kings.
Kind of Josephine; asks for the number of high honours (ace, king or queen) in trumps 6♣ = 0, 6♦ = 1, etc.
First− and second−round controls are treated as equals Weaker and stronger types after 1♥/1♠ openings 1♥ – 3♠ = weaker Splinter (9–12 HCP), any shortage, 3NT asks 1♥ – 3NT = regular Splinter (12–16 HCP), spade shortage 1♠ – 3NT = weaker Splinter, any shortage, 4♣ asks 1♥/1♠ – 4♣/4♦/4♥ = regular Splinters (12–16 HCP) An unusual shift jump agrees bidder's own suit only if partner has not shown any suit.
Asks partner to bid the grand slam with a void in the splinter-suit.
Direct cue bid is game-invitational, or game forcing with flat distribution and defensive values.
Pass and then double after 2♥/3♥ in the next round is for takeout of hearts: Fourth hand's live double is for takeout: Michaels cue bid – unlimited Jump cue bid shows either a solid suit and asks for a stopper or shows any game-forcing one-suiter hand.
Other bids show the same shape as versus a strong no trump and promise opening values.