The only acceptable time to ask for an undo is when you have misclicked.
If you make a poor bid or play or for any other reason, it is inappropriate to ask for an undo.
Undo's in automated tournaments as well as games in the Solitaire section is not available.
An Undo in a private tournament is allowed if the Tournament Director included this option in their tournament settings. It is up to a Tournament Director to allow / disallow undo's.
There are only a few circumstances under which it is appropriate to ask for a redeal:
- If a player at a duplicate table has seen the current deal before (impossible in theory)
- If a player has left the table in the middle of a hand
- If there appears to be a software problem involving the current deal