Thanks for letting me join. Not yet a director but my research does not make it clear if declarer or dummy can revoke and, if they do, how do I fix it?
I'd recommend looking directly in the Laws of Bridge for your research; it's often easier to go straight to the source! You can download a copy from the EBU website if you don't have one already.
Let's take the questions one at a time:
if declarer or dummy can revoke
Law 61A defines what a revoke is. There are two ways to revoke: one is to fail to follow suit to the lead of the trick when able to do so (Laws 44C and 44D); the other is to fail to follow instructions about what cards/suits can be played (that are imposed as part of a penalty for an irregularity). "You have to play a card of this suit because you broke the rules earlier" is something that, as far as I'm aware, can only happen to defenders (normally as a consequence of penalty cards), so a declarer or dummy can't revoke like that. However, it's definitely possible for declarer or dummy to fail to follow suit, so it is possible for declarer or dummy to revoke.
if they do, how do I fix it?
Dealing with a revoke by declarer is fairly similiar to dealing with a revoke by a defender: assuming it happened on the first 11 tricks, there's a period of time (until the offending side plays to the next trick) in which the revoke can be corrected, and after that, it becomes established and penalties will apply (Laws 62 and 63). One major difference in terms of revoke corrections is in Laws 62B and 62C: if a defender revokes (or both sides revoke!), any of the defence's cards that are retracted while correcting it become major penalty cards (they're the offending side and thus are penalised for the extra information they gained); if declarer or dummy revokes, cards retracted by the defence don't become penalty cards (because they didn't do anything wrong). In this case, the disadvantage for the declarer for revoking comes from Law16C: if the defenders saw each others' cards as a result of the declarer's revoke, they're entitled to make full use of that information (whereas the declarer can't make use of the information they gained from seeing the defender's actions, and has to take actions counter-suggested by that information unless it would be illogical to do so).
If a revoke by the declaring side does become established, a revoke by declarer is penalised exactly the same way as a revoke by a defender (with tricks being removed from the offending side's total and added to the non-offending side's; Law 64A). However, there is a special case for dummy here: Law 64B3 prevents there being any automatic penalty if dummy revokes. That doesn't mean that the revoke by dummy won't get penalised, but it's up to the Director's discretion to determine whether an adjustment is necessary, and if so what it is (Law 64C1); the Director will decide based on what would likely have happened without the revoke, favouring the non-offenders (the defence) if there's doubt (Law 12).
Revokes on trick 12 have their own rules (Law 62D; this is because normally it's possible to piece together what "should have happened" because there's so little choice left, so you don't need the normal penalties), and are handled the same way for the declaring side as for the defence.
@Johnathan said:
Thanks for letting me join. Not yet a director but my research does not make it clear if declarer or dummy can revoke and, if they do, how do I fix it?
The EBU sell a little booklet called "how to run a club duplicate" that's rather useful as an introduction (it also comes with the course from the EBU of the same name).
There's also a simplified version of the laws available from another provider (which I won't name out of courtesy to the EBU), which nicely states: "One of the silliest sayings in bridge is ‘Dummy can’t revoke’. Of course he can. What they mean is that there is no automatic penalty."
Comments
I'd recommend looking directly in the Laws of Bridge for your research; it's often easier to go straight to the source! You can download a copy from the EBU website if you don't have one already.
Let's take the questions one at a time:
Law 61A defines what a revoke is. There are two ways to revoke: one is to fail to follow suit to the lead of the trick when able to do so (Laws 44C and 44D); the other is to fail to follow instructions about what cards/suits can be played (that are imposed as part of a penalty for an irregularity). "You have to play a card of this suit because you broke the rules earlier" is something that, as far as I'm aware, can only happen to defenders (normally as a consequence of penalty cards), so a declarer or dummy can't revoke like that. However, it's definitely possible for declarer or dummy to fail to follow suit, so it is possible for declarer or dummy to revoke.
Dealing with a revoke by declarer is fairly similiar to dealing with a revoke by a defender: assuming it happened on the first 11 tricks, there's a period of time (until the offending side plays to the next trick) in which the revoke can be corrected, and after that, it becomes established and penalties will apply (Laws 62 and 63). One major difference in terms of revoke corrections is in Laws 62B and 62C: if a defender revokes (or both sides revoke!), any of the defence's cards that are retracted while correcting it become major penalty cards (they're the offending side and thus are penalised for the extra information they gained); if declarer or dummy revokes, cards retracted by the defence don't become penalty cards (because they didn't do anything wrong). In this case, the disadvantage for the declarer for revoking comes from Law16C: if the defenders saw each others' cards as a result of the declarer's revoke, they're entitled to make full use of that information (whereas the declarer can't make use of the information they gained from seeing the defender's actions, and has to take actions counter-suggested by that information unless it would be illogical to do so).
If a revoke by the declaring side does become established, a revoke by declarer is penalised exactly the same way as a revoke by a defender (with tricks being removed from the offending side's total and added to the non-offending side's; Law 64A). However, there is a special case for dummy here: Law 64B3 prevents there being any automatic penalty if dummy revokes. That doesn't mean that the revoke by dummy won't get penalised, but it's up to the Director's discretion to determine whether an adjustment is necessary, and if so what it is (Law 64C1); the Director will decide based on what would likely have happened without the revoke, favouring the non-offenders (the defence) if there's doubt (Law 12).
Revokes on trick 12 have their own rules (Law 62D; this is because normally it's possible to piece together what "should have happened" because there's so little choice left, so you don't need the normal penalties), and are handled the same way for the declaring side as for the defence.
The EBU sell a little booklet called "how to run a club duplicate" that's rather useful as an introduction (it also comes with the course from the EBU of the same name).
There's also a simplified version of the laws available from another provider (which I won't name out of courtesy to the EBU), which nicely states: "One of the silliest sayings in bridge is ‘Dummy can’t revoke’. Of course he can. What they mean is that there is no automatic penalty."