In a nutshell
- The combat phase consists of 5 steps:
- Beginning of Combat step
- Declare Attackers Step
- Declare Blockers Step
- Combat Damage Step
- End of Combat Step
- During each step, first perform any turn-based actions (declaring attackers or blockers, assigning and dealing combat damage), then each player gets priority to cast spells or activate abilities.
- The process for declaring attackers is:
- Decide which creatures are attacking
- Declare which player/planeswalker each creature is attacking
- Evaluate to see if the set of attackers is legal (Loyal Pegasus, Valley Dasher, etc.)
- Tap the attacking creatures (except the creatures that have vigilance)
- Pay costs to attack (Like Propaganda or Oppressive Rays)
- Declaring blockers follows similar steps, modified appropriately
- A set of attackers or blockers is legal if it fulfills the maximum possible number of requirements (effects that say a creature must attack or block, or that it must do so if some condition is met) without violating any restrictions (effects that say a creature cannot attack or block, or that it can’t unless some condition is met).
- Players are not required to pay a cost to allow attacking or blocking even if it increases the number of requirements that would be met.
- After declaring blockers, but still in the declare blockers step, the attacking player declares the damage assignment order for all his attacking creatures. Then the blocking player declares the damage assignment order for all his blocking creatures (though this can only come up if a creature is somehow assigned to block two different creatures, which normally can’t happen). Then each player gets priority to cast spells and activate abilities.
- If a creature changes controllers during combat, it is removed from combat. This means that it is no longer considered an attacking or blocking creature and it does not deal or receive combat damage.
- Some effects put a creature onto the battlefield attacking or blocking. Such effects bypass the normal process of declaring attackers or blockers. This leads to the following important consequences:
- The creature is never declared as an attacker or blocker, so it won’t cause abilities like “whenever a creature attacks you” or similar to trigger.
- The game doesn’t get a chance to evaluate whether the creature would normally be able to attack or block because that check is part of the process of declaring attackers or blockers. Similarly, costs that would be required to enable attacking/blocking are bypassed for such creatures.
A: No. Paying costs to attack is part of the process of declaring attackers, and no player gets priority to activate abilites while this process is being carried out [ref CR 508.1 et seq., which outline the steps].
Note: As seen in that passage of the CR, Amy actually will decide to attack with Grizzly Bears before she pays the 3 mana.
Q: Amy controls 2 Loyal Pegasuses, but no other creatures. Can she attack with both of them?
A: Yes. The attacking player chooses all the creatures that will attack in one action, then the game evaluates whether the proposed set of attackers is legal. If Amy chooses to attack with both Pegasuses, the game will see that neither of them is attacking alone, so the set of attackers does not violate any restrictions and will be considered legal.
Q: Amy controls a Goblin War Drums and attacks with a Hill Giant. Nicole controls a Grizzly Bears that’s enchanted with Oppressive Rays and a Razorgrass Screen. What legal blocks are available to Nicole?
A: Blocking with just Grizzly Bears or just Razorgrass Screen is not legal because these both violate the restriction imposed by Goblin War Drums. If Nicole blocks with both creatures, this will satisfy the Razorgrass Screen’s requirement without violating Goblin War Drums’ restriction. Nicole would have to pay 3 to enable the bear to block if she chooses this option. Alternatively, she may declare no blocks. This is possible because players are not obligated to pay a cost to attack or block, even if doing so would increase the number of requirements that are met.
Note: Without the Oppressive Rays, there is no choice. Nicole must choose the set of blockers that maximizes the requirements fulfilled without violating any restrictions. In this case, that means blocking with both creatures.
A: No. After blockers are declared, Amy must announce her Ox’s damage assignment order. She cannot assign damage to a creature unless all creatures that she ordered before it have received lethal damage. In this case, that means she can deal 2 damage to either Courser, but she can’t deal 1 damage to each of them.
Q: Amy casts Pyroclasm, then attacks with a 5/5. Nicole blocks with a 2/2 indestructible creature, a 6/6 creature, and a 4/4 creature. Amy announces that she will assign damage to them in that order. What happens?
A: Amy must assign lethal damage to each creature before assigning any damage to the next one. Lethal damage counts damage that is already marked on the creature, so she doesn’t need to assign any damage at all to the 2/2. She must assign at least 4 damage to the 6/6, which means that she can assign 1 damage to the 4/4. After combat, her 5/5 will die, along with Nicole’s 6/6. Nicole’s 4/4 will live, but it will have 3 damage on it, and any additional damage this turn will kill it.
A: Nothing much. The Pegasus was legally declared as an attacker. The game doesn’t go back in time to “fix” itself now, even though the pegasus couldn’t be declared as an attacker if Amy had to declare attackers again.
Q: Nicole has a Jace, Architect of Thought and used it +1 ability last turn. Amy attacks with Brimaz and puts a soldier token into play attacking. What will the soldier token be attacking? What will be the soldier’s power when it assigns damage?
A: Because Brimaz’s effect doesn’t specify what the token is attacking, Amy chooses at the point when it’s put onto the battlefield. She can have it attack any opponent (if there are more than one), or any planeswalker controlled by an opponent.
Because the soldier never “attacked” (it was never declared as an attacking creature), Jace’s trigger doesn’t affect the soldier token.
Note: Say that Nicole also controled a Gideon Jura and had used its +2 ability last turn. Amy would have to attack Gideon with her Brimaz. Because the token is put onto the battlefield attacking, bypassing the normal process of declaring attackers, the token can be put onto the battlefield attacking whatever Amy chooses. It is not subject to the requirement imposed by Gideon.
Note: If the Brimaz was blocking, there would be no choice in what to block because Brimaz’s effect says that the token must block whatever creature Brimaz is blocking.