Maximal overcall double

A double by opener on the second round when both sides have found a fit and there is no room for any other game try. The double shows a hand strong enough to invite game.

         South   West    North   East
         1S      2H      2S      3H

It follows that a bid of 3S by South would suggest simply a desire to contest the partscore. In this example, if the defending side's suit were diamonds or clubs, a double would have its ordinary penalty meaning.