Does banding still exist and how does it affect combat damage assignment?

Banding is a legacy keyword ability that still exists in the Magic Comprehensive Rules (CR 702.22). While no cards printed after the early days of Magic have received it, cards like Serra Angel (in certain older printings) and Banding-themed creatures remain fully legal and functional in formats where they are legal.

Normally, an attacking creature's controller assigns its combat damage, and a blocking creature's controller assigns that blocker's damage. Banding changes this: if an attacking creature with banding (or a band of multiple creatures where at least one has banding) is blocked, the attacking player chooses how all combat damage from the entire blocking group is divided among the banded attackers (CR 702.22j). Conversely, when a creature with banding blocks, the defending player chooses how the attacking creature's damage is assigned among all creatures banded together as blockers (CR 702.22k).

The key restriction is that damage assignment must still be legally lethal to each creature in order — you cannot simply redirect all damage away from one creature without assigning lethal damage to it first, per the regular combat damage assignment rules (CR 510.1).

Example: Your opponent attacks with a 4/4. You block with two creatures: a 1/1 with banding and a 2/2. Because a banding creature is blocking, you (the defending player) choose how the 4/4's 4 damage is split — say, 1 to the 1/1 and 3 to the 2/2 — rather than your opponent deciding.

Banding also allows multiple attackers to band together (at least one must have banding), forming a group that is blocked or unblocked as a single unit, giving the attacking player similar damage-assignment control (CR 702.22b–702.22i).