Weak Two Opening bids are a preemptive bid. Weak Two bids tell your partner that you have at least a 6-card suit and 6-10 HCP with two or more high-cards in the bid suit. Generally bidding Weak Twos does not exclude a 4 card side-suit holding in another suit. Weak 2's have strong bids as well so there is much more use for a systems that covers a large variety of hands and is much adopted by more advanced players although not always.

Guidelines for Weak 2 Bids

1. If the preemptive bid is a Major suit, then you are usually telling partner that you don't have any interest in the other Major suit
2. A preempt as an overcall after oppositions opening on the one level should be at least one level higher and in a higher-ranking suit than the opening bid.
3. If the preemptive bid is an overcall after after oppositions opening bid on the one level is in a lower-ranking suit, then the preemptive bid should be at least two levels higher.
4. You are showing that you do not have an opening hand.
5. When deciding to make a Preempt the vulnerable or non-vulnerable, and counting the number of winning/losing tricks should be carefully considered.

Exercise: What should you open this hand?