How to Overcall in Bridge Bidding
If a bridge opponent opens the bidding, you may be able to interfere with a bid (or bids) by overcalling. You overcall when you bid a different suit than the suit your opponent bid.
You may prevent your opponents from locating their best fit, and do they ever hate that! Equally important, your opponents may reach their best contract, but you can tip off your partner to the winning opening lead.
No matter how much you like your opponents, don’t resist the temptation to mess up their bidding. It’s a jungle out there. Here’s your short list of the different kinds of overcalls:
One-level overcall: If you bid a suit at the one level, you make a one-level overcall.
Two-level overcall: Bidding a suit at the two-level, surprise, a two-level overcall.
Weak jump overcall: Jumping the bidding (skipping a level) in another suit is a weak jump overcall.
Notrump overcall: Bidding 1NT is a one notrump overcall.
You can start harassing the opposition as soon as they open the bidding. At least consider overcalling every time the opponents open the bidding. To overcall, you need a strong five- or six-card suit. If you have that strong suit, high card points (HCP) become less important.
Overcalls apply whether the player who opened the bidding is on your right (you’re second to bid) or on your left (you’re fourth to bid).
When bidding defensively after your opponents have opened, you want to achieve maximum irritation at minimum risk, while still hoping to bid constructively when you have a good hand. An ambitious target, but you can manage it.