As an opening Edit

A 3 opening is preemptive in every system.

As a response Edit

To a 1/1 opening Edit

1/1 - 3 is a double jump shift, which is either a weak jump shift, showing less than 6 HCPs and 7 s, or a splinter showing support and void or singleton in s.

To a 1 opening Edit

1-3 is a double raise, usually a limit raise.

To a 1 opening Edit

1-3 is a jump shift, which may be played as weak, showing less than 6 HCPs and 7 s, or strong, showing a single-suiter with slam interest.

To a 1NT opening Edit

The 3-level responses of a 1NT opening have many possible meanings, which depend on agreements.

To a strong 2 opening Edit

A jump response to a strong 2 opening shows a very strong single-suiter and slam interest.

To a weak 2 opening Edit

A single raise of a weak two bid is preemptive and to play.

To a 2/3/3 opening Edit

This shows a strong hand and a self-sufficient suit, and is forcing.

As an overcall Edit

A jump overcall of 3 is usually equivalent to a 3 opening, which is preemptive.