Can I block with a creature which I just put on the battlefield with Flash (choosing not to pay it's mana cost minus 2C) during the declare blockers step before sacrificing it?
Similarly, can I block with a creature that has an Evoke cost which I am somehow able to cast during the declare blockers step?
No, to both. Flash has you sacrifice immediately as it resolves, so the creature won't be around long enough to be declared as a blocker. And when you cast a creature for its evoke cost, it will be sacrificed when the evoke triggered ability resolves. So, likewise, it won't stick around long enough to be declared as a blocker.
Also, note that you have to put a creature onto the battlefield *before* the declare blockers step if you want to declare it as a blocker.
So that's why certain tokens enter “tapped and attacking” sometimes and yet don't count towards attack triggers as they were never declared attackers by the player themselves? Am I correct in assuming that the wording for it to work would be something like saying that the creature entering during the declare blockers step was specifically entering “blocking” or “tapped and blocking”? And that it wouldn't trigger any “when this creature blocks..” triggers yet?
So that's why certain tokens enter “tapped and attacking” sometimes and yet don't count towards attack triggers as they were never declared attackers by the player themselves?
To be declared as attacker or blocker, a creature has to be around during the turn based action of the declare attackers step or the declare blockers step respectively. Which happen as the first thing in those steps before any player gets priority during those steps.
Am I correct in assuming that the wording for it to work would be something like saying that the creature entering during the declare blockers step was specifically entering “blocking” or “tapped and blocking”? And that it wouldn't trigger any “when this creature blocks..” triggers yet?
If a creature enters blocking a certain creature, then that attacking creature becomes blocked, which triggers "becomes blocked" triggers for that attacker. But the new blocker will not have any "blocks" triggers go off because it was never declared as blocker.
509.5e If an ability triggers when a creature blocks or becomes blocked by a particular number of
creatures, the ability triggers if the creature blocks or is blocked by that many creatures when
blockers are declared. Effects that add or remove blockers can also cause such abilities to
trigger. This applies to abilities that trigger on a creature blocking or being blocked by at least a
certain number of creatures as well.
509.7. If a creature is put onto the battlefield blocking, its controller chooses which attacking creature
it’s blocking as it enters the battlefield (unless the effect that put it onto the battlefield specifies
what it’s blocking), then the active player announces the new creature’s placement in the blocked
creature’s damage assignment order. The relative order among the remaining blocking creatures is
unchanged. A creature put onto the battlefield this way is “blocking” but, for the purposes of trigger
events and effects, it never “blocked.”
Can I block with a creature which I just put on the battlefield with Flash (choosing not to pay it's mana cost minus 2C) during the declare blockers step before sacrificing it?
Similarly, can I block with a creature that has an Evoke cost which I am somehow able to cast during the declare blockers step?
Chur
Also, note that you have to put a creature onto the battlefield *before* the declare blockers step if you want to declare it as a blocker.
Commander/EDH Decks:
BRG The Blood of Jund - Kresh the Bloodbraided BRG
WR The Blades of Goldnight - Gisela, Blade of Goldnight WR
Cheers
Edud
To be declared as attacker or blocker, a creature has to be around during the turn based action of the declare attackers step or the declare blockers step respectively. Which happen as the first thing in those steps before any player gets priority during those steps.
If a creature enters blocking a certain creature, then that attacking creature becomes blocked, which triggers "becomes blocked" triggers for that attacker. But the new blocker will not have any "blocks" triggers go off because it was never declared as blocker.
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