Can you use an activated ability after blockers are declared?

yes, it’s legal. both players receive priority in each step of the combat phase. once blockers are declared he can still activate abilities/cast spells.

Can you respond to declare blockers?

You can’t respond to blockers being declared the way you could respond to a player casting an Instant, as declaring blockers is a turn-based action that doesn’t use the stack.

Do you tap when blocking?

A creature must be untapped in order for it to block. Unlike attacking, the act of blocking does not cause the blocking creatures to tap, and creatures with summoning sickness can block.

Who decides blocker order?

Once the defending player declares his or her blockers, for each attacking creature that is being blocked by multiple creatures, the attacking player chooses the blocking order*.

How is damage assigned to multiple blockers?

If exactly one creature is blocking it, it assigns all its combat damage to that creature. If two or more creatures are blocking it, it assigns its combat damage to those creatures according to the damage assignment order announced for it. This may allow the blocked creature to divide its combat damage.

Can you cast instants after your opponent declares blockers?

If you have moved to the Declare Blockers step, it’s too late, since the very first thing that happens is the defender declares blockers. Nobody has priority until after that happens. To answer the question in your title, yes, each player receives priority and can cast instants after blockers are declared.

How to declare blockers in turn based action?

This turn-based action doesn’t use the stack. To declare blockers, the defending player follows the steps below, in order.

When does an ability trigger when a blocker is declared?

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.

What happens when you declare a blocker in RuneScape?

509.2a During the declare blockers step, if a blocking creature is removed from combat or a spell or ability causes it to stop blocking an attacking creature, the blocking creature is removed from all relevant damage assignment orders.