Doubles are a bid that does not raise the level of the auction (like a pass). They were introduced to stop players greatly overbidding. The effect of a double is twofold. If the contract is defeated then penalties are much greater. If on the other hand the contract is made, the rewards are greater.

The penalties

Down non-vuln vuln

1 100 200

2 300 500,

3 500 800

4 800 1100

A reminder that un-doubled contracts you lose 50/100 points per trick that you are down depending upn vulnerability

The rewards for making a doubled contract

The contract points are doubled, there is 50/100 points for the ‘insult’ depending upon vulnerability and overtricks are 100/200 per trick

For rubber bridge scoring, everything except the contract points go above the line. You can be doubled into ‘game’. For example 2 hearts doubled and made gives you 4 x 30 (120) pts instead of 60pts

If you are confident of making the doubled game you may ‘re-double’ and then everything doubles up again, but this rare amongst good players

There are other uses for the double bid and these will be explained in part 2