[Prachandra]

I recently had a misunderstanding with this auction:

1♣ - pass - 1♥ - 2♦ - double

What does that double mean?

[Stephen Tu]

It depends on partnership agreement. There is no real standard meaning, what is expected depends a lot on the experience level of your partner, when they learned bridge, and probably also regional preferences.

The most common meanings are:
- 3 card heart support (in contrast to 4+ heart support which supports hearts at the appropriate level), a so called "support double", when 4th hand has overcalled *below* 2 of partner's suit response.
- good hand, takeout or "do something intelligent"
- penalty (for old fashioned bidders, doubles are default for penalty, opposite of modern tendencies)

[Zelandakh]

Hi Prachandra and welcome to the BBO forums. As Stephen has already mentioned, this depends on agreements. What I would like to add to his post is that it also depends on system and location. In America, where strong NT + 5 card majors dominates, the most common meaning is the Support Double. In France and Germany, also mostly strong NT + 5 card major, the Support Double is also used but now with a twist - it also promises extra values. In England though, where weak NT + 4 card majors are the predominant system, the most common meaning is the "Strong NT Double", which is basically just showing that you want to compete but do not have a suitable call available.

So if you were to ask me what the double meant without agreement, it would actually be completely different for me depending on who I was playing with. With Stephen or Winston I would be sure it was Support; with Rainer or Codo I would suspect Support + extras; with Tramticket (and probably also nige or Cyberyeti) it would be a Strong NT Double. In other words, there is no definitive answer to your question without some additional context. Hopefully between these 2 posts you have enough of that to work out the right answer for you.

[silvr bull]

I will add a small note to the excellent replies above. It is always best to discuss and agree with partner about what bids mean, but some bidding situations can be so complex that they are not discussed until the "Who done it?" postmortem. In an effort to simplify where possible and to reduce the potential for confusion, I tell my partners this about doubles:

I like a simple rule on doubles: If you have not bid, my double below 3NT is 100% takeout, except of artificial bids like Stayman or transfers.

If you have bid, my double is 100% penalty, except for simple negative (or support if agreed) double, or responsive double when they raise their own suit.