What is the penalty for failing to follow suit?

Question

Assume the mistake is unintentional, what course of action should be taken when this occurs and is discovered?

If the person discovers themselves that they earlier made the mistake, is the penalty different than if an opponent discovers it?

Answer 1

In Duplicate Bridge the penalty for a revoke (failing to follow suit) is very clear.

The official rules handle revokes in Laws 61 to 64. Wikipedia's summary of 61-64 is

A revoke may be corrected (correct card substituted) without trick penalty before any player of the offending side plays to the next trick; otherwise, it becomes established. If a revoke is corrected, the exposed card becomes a penalty card and the opponents may change their played cards as they see fit (however, the revoking side may not take advantage of those seen cards—see Alcatraz coup). When a revoke is established, in general, one of subsequent tricks won by the offending side is transferred to the opponents. If the revoke card has won the trick, that trick is transferred too. (If the offending side did not win any subsequent tricks, no penalty is assessed). Additional tricks can be transferred if the revoke has caused more damage to the opponents than was redressed by those penalties.

If the revoke is not immediately corrected, there is no difference in penalties based on the person who establishes the revoke. It makes no difference whether the mistake was intentional or unintentional.

Answer 2

Failing to follow suit is called a "revoke" or "renege" when that person subsequently plays a card from that suit (assuming that the mistake was not discovered and corrected in time). The governing law is the 2017 amendment (to the earlier 2007 version) of Law 64 of the ACBL.

The penalty is normally one trick. But there are two major exceptions.

a) There could be a second trick per Law 64:

1, "When a revoke is established, and the trick on which the revoke occurred was won by the offending player*, at the end of the play the trick on which the revoke occurred is transferred to the non-offending sidetogether with one of any subsequent tricks won by the offending side.
2. and the trick on which the revoke occurred was not won by the offending player* then, if the offending side won that or any subsequent trick, after play ends one trick is transferred tothe non-offending side.

Note: 2), above, is effected by placing the reneged card face up on the table.

b) If "there is no rectification" (e.g. because the offending side loses the reneged trick, and all tricks subsequent to the discovery of the renege), the penalty is zero. (The offense didn't cause any damage.)

Answer 3

The revoke (renege) laws are complicated!

If a player discovers that they have revoked before the side has led to the next trick OR if the revoke occurred at trick 12 OR both sides have revoked at the same trick and only one has led to the next, then the revoke is NOT established. It must be corrected and, if a defender, the revoke card becomes a Major Penalty card. The player after the revoker can change their card without penalty (information about the card withdrawn is Authorised for the non offending side but unauthorised for the offending side): if they do then the partner of the revoker can change their card - but the original one remains a major penalty card.

If the revoke IS established then there may be an automatic trick adjustment - this does not happen if the card that was used to revoke was already visible i.e in dummy or a major penalty card, at trick 12 (see above), if it is a second revoke in the same suit, or if both sides have revoked on the same trick, if the round has ended or the non-offending side has called on the next hand. Law 64 B

The automatic trick adjustment is:

If the revoke card won the trick - this almost always means that it trumped in the trick (although it could be that a player was required to lead a suit because of a previous infraction and failed to do so when they could) - then THAT trick is transferred over to the other side. ONE more trick is transferred over but ONLY if the offending side won the trick AFTER the revoke.

Finally there are some situations where the non-offending side are not adequately compensated for the effects of the revoke - in which case the Tournament Director restores Equity.

In summary - when attention is drawn to a revoke- call the director! Do not accept or agree to any statement made by the opponents as to the correct rectification.