Does deathtouch work with trample to assign only 1 damage to a blocker and trample the rest?

Trample allows a creature to assign its combat damage to the defending player (or planeswalker) once each blocker has been assigned lethal damage (CR 702.19b). Normally lethal damage equals a creature's toughness minus any damage already marked on it. Deathtouch changes this: any amount of damage dealt by a source with deathtouch is considered lethal (CR 702.2c, 702.19b).

These two rules interact directly. When you assign combat damage with a trampling creature that has deathtouch, the minimum you must assign to each blocker is just 1 damage — that single point counts as lethal because of deathtouch. All remaining damage can then be assigned to the defending player or planeswalker.

The interaction is explicitly confirmed in CR 702.19b: 'if a creature has deathtouch, 1 damage is lethal' for the purpose of the trample excess calculation. This is not an opinion or ruling — it is written directly into the trample rule.

Example: You attack with a 6/6 creature that has both trample and deathtouch. Your opponent blocks with a 5/5. You need to assign only 1 damage to the 5/5 (lethal due to deathtouch) and may assign the remaining 5 damage to the defending player. The 5/5 will die, and the player takes 5.

Note that you must still assign at least 1 damage to each blocker — you cannot assign 0 to a blocker and send all damage through. Also, if a blocker has protection or another damage-prevention effect, the interaction may change how much damage actually resolves.