A double in bridge bidding can be either a takeout double, used to ask partner to bid, or a penalty double, used when a player thinks the opposition won't make their contract.
How can I tell whether a double is penalties or takeout? The state of the auction determines whether a double was meant for takeout or for penalties.
- Doubles of low level suit contracts are takeout.
- Doubles of high contracts and notrump bids are penalties.
X means double