The enemy overcalls the opening bid.

Double is informative through 2. It shows two hand types:

  1. Support (3+ cards) for the unbid suits and about 8 - 11 HCP. Opener makes a limit bid if possible.
  2. A suit of its own and a game force. If it turns out that the suit could have been bid originally (i.e. without a double) below the 2 level in opener's suit, then it shows a semi-solid suit. Otherwise it shows a 5+ card suit.

No Trump bids are natural and limit.

Jump shifts are Fit showing promising a 5+ card suit and 4+ in opener's suit.:-O (this is a change from the web based system write-up).

New suits are natural and forcing unless the call made is above the 2 level of opener's suit when a negative double is available. This is our definition of a negative free bid. Examples:

1(1)?
2 is a force
2 is a non-force (negative free bid)
1(3)?
all new suits are forcing since a negative double is not available.

The enemy overcalls the suit showing responses

Opener rebids as in natural systems; bids at the two level do not show extra values, at the three level they do. We hate to lose our 5+ card major, so we make allowances for opener holding a true dog when he bids a major (either re-bids or bids for the first time) at the two level.

They overcall the forcing 1N response

If opener is able to make his normal response (i.e. the overcall has not taken away bidding space), then all is normal and relays can continue. Otherwise, relays are off. They are also off if overcaller's partner interferes further. Relays are off, regardless of whether or not opener's second bid was bumped up (as per agreement on 8/31/2022).

Examples:

1 P 1N 2
2 P ?
1 P 1N 2
3 P relays off, opener has shown extra playing strength,
but there is no pre-defined relay type sequence now available

They double the opening bid:

Other actions by Forcing NT hand:

Actions by Forcing NT hand after RHO interferes over opener's second bid:

- RHO bids a suit:

  1. RHO doubles