You're on the money bubble of a live tournament. The bully stack has been beating up on middle stacks while giving the shortest stacks a free pass. This is standard bubble procedure for a bully stack.
The action folds to the bully in the small blind, who completes instead of raises because the short stack is in the big blind. The big blind checks his option.
The flop and turn go check/check, check/check. On the river the bully mucks his hand instead of checking.
Is that legal? Is it ethical?
Would it be any different if the bully had limped in from another seat and then mucks his hand after the short stack in the big blind checks?
What if the bully mucks his hand in position but out of turn?
This is copy-pasted from a forum response on twoplustwo.com:
This is from the TDA, which governs tournaments rather than cash play, but here's what it has to say:
45: Non-Standard Folds
Anytime before the end of the last betting round of a hand, folding in turn when facing a check or folding out of turn are both binding folds and may be subject to penalty.
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Nothing illegal or unethical about it, as described. If it were a three-handed situation, folding out of turn would be frowned upon from a rules standpoint. It would probably only draw a warning though. And folding in turn, but with others left to act, would really be kinda low-budget, in terms of ethics, although not illegal.
The term for this action, which can be done on any street, is “ checking out”. It is considered bad form in multi-way pots, because it gives the remains players free information.