Mishra's War Machine

If a creature in combat has banding, its controller assigns damage for creatures blocking or blocked by it.

wotc · 2009-10-01

If a creature with banding attacks, it can team up with any number of other attacking creatures with banding (and up to one nonbanding creature) and attack as a unit called a "band." The band can be blocked by any creature that could block a single creature in the band. Blocking any creature in a band blocks the entire band. If a creature with banding is blocked, the attacking player chooses how the blockers' damage is assigned.

wotc · 2008-10-01

A maximum of one nonbanding creature can join an attacking band no matter how many creatures with banding are in it.

wotc · 2008-10-01

Creatures in the same band must all attack the same player or planeswalker.

wotc · 2008-10-01

You may choose to take damage or to discard. You can't avoid taking damage if you have no cards to discard.

wotc · 2004-10-04