MUD refers to the order in which a defender plays three small cards. The opening lead is the middle card, followed by the higher card and then lower card, In comparison to leading "low from three small", MUD tries to convey weakness in the suit. At the same time, MUD tries to avoid being confused with a doubleton when the higher card is played at the defender's second turn.
Examples:
- 9-5-2 — lead the 5.
- 8-6-3 — lead the 6.
- 9-8-7 — some players would lead the 8, but others would lead the 9 (top of sequence). This requires partnership discussion.