Magic: The Gathering Comprehensive Rules Changes - Masters Edition to Lorwyn

Old rule (Masters Edition)	New rule (Lorwyn)
308.4. → 308.5. [Click to view all changes.]
308.4. If no creatures are declared as attackers, skip the declare blockers and combat damage steps.	308.5. If no creatures are declared as attackers or put into play attacking, skip the declare blockers and combat damage steps.

Old rule (Masters Edition)

New rule (Lorwyn)

308.4.

If no creatures are declared as attackers, skip the declare blockers and combat damage steps.

308.5.

If no creatures are declared as attackers or put into play attacking, skip the declare blockers and combat damage steps.