Application of Law 12

There is still some strange wording in Law 12 covering what was previously described as the distinction between "consequent" and "subsequent" damage; "subsequent" damage could have been due to wild or gambling action by the non-offending side, by their serious error, or just "failure to play bridge". However, I think the effects are clear: for the offending side (OS) we adust if they obtain a table result better than they would have without the infraction; but the non-offending side (NOS) do not get an adjustment for damage which is self-inflicted, defined as due to a serious error or wild or gambling action (WoGA).

In practice there are four cases: all damage is self-inflicted, some is self-inflicted, no self-inflicted damage, or no damage at all. There are scores we have to consider

1. the score for the Actual table result (including any serious error or WoGA)
2. the score for the result Before infraction (assigned by Law 12C1c or Law 12C1e)
3. (≥ A) the score for the result that Could have been scored, with the infraction but without serious error (could be weighted?)

The overall damage can be divided as

• Real damage: D_R = B − C
• Self-inflicted damage: D_S = C − A

Starting from C ≥ A there are four cases

• C ≥ A > B: no advantage, no damage, no adjustment;
• C ≥ B ≥ A: all damage self-inflicted, no real damage D_R ≤ 0 (virtual damage), NOS get A, OS get B;
• B > C = A: no self-inflicted damage, D_S = 0, NOS get B, OS get B;
• B > C > A: real damage and some self-inflicted.

In the final case, the OS get B and the NOS get A + B − C. The adjustment for the non-offending side can be seen as either

• actual score + real damage: A + D_R = A + (B − C); or
• adjusted score − self-inflicted damage: B − D_S = B − (C − A) = A + B − C.

Examples

NS bid to 4H and EW "use UI" to compete to 4S, which is doubled. In defending 4SX, NS might revoke (a serious error) and lose a trick they would otherwise score. The result in the other room is 4H=, NS +420. This is the normal result in 4H, so B (the result before the infraction) is 0 IMP. The type of adjustment depends on the table result.

4SX-1 NS +100. Revoke

A = IMP(100-420) = −8 IMP. Without the revoke: 4SX-2 NS +300. C = IMP(300-420) = −3 IMP.

Real damage D_R = 3 IMP, self-inflicted damage D_S = 5 IMP.

Offending side (team of EW) get 0 IMP, non-offending side (team of NS) get 0 + (−8) − (−3) = −5 IMP.

4SX-2 NS +300. Revoke

A = −3 IMP. Without the revoke: 4SX-3 NS +500. C = IMP(500-420) = +2 IMP. No real damage (D_R < 0).

Offending side get 0 IMP, non-offending side get −3 IMP (table result).

4SX-2 NS +300. No revoke

A = C = −3 IMP. No self-inflicted damage (D_S = 0). Both sides get 0 IMP.

4SX-3 NS +500.

A = +2 IMP. No damage. Table result for both sides.