Magic: The Gathering Comprehensive Rules Changes - Eventide to Shards of Alara

Old rule (Eventide)	New rule (Shards of Alara)
306.5. [Click to view all changes.]
306.5. An attacking creature is attacking alone if no other creatures are attacking. A blocking creature is blocking alone if no other creatures are blocking.	306.5. A creature attacks alone if it's the only creature declared as an attacker during the declare attackers step. A creature is attacking alone if it's attacking but no other creatures are. A creature blocks alone if it's the only creature declared as a blocker during the declare blockers step. A creature is blocking alone if it's blocking but no other creatures are.

Old rule (Eventide)

New rule (Shards of Alara)

306.5.

An attacking creature is attacking alone if no other creatures are attacking. A blocking creature is blocking alone if no other creatures are blocking.

306.5.

A creature attacks alone if it's the only creature declared as an attacker during the declare attackers step. A creature is attacking alone if it's attacking but no other creatures are. A creature blocks alone if it's the only creature declared as a blocker during the declare blockers step. A creature is blocking alone if it's blocking but no other creatures are.