Hello magicjudge, sorry this is going to be a long one but our circle needs to clear this up. Regarding combat phase and instants, once the combat phase begins, the defending player may cast instants by mentioning "before combat I cast yadiyadiyada" to exile (Swords), tap (twiddle) or destroy (murder) because once declared as an attacker damage is going to dealt. But what about pumping a creature, does it have to be done before declaring attackers (which takes away any element of surprise) ?
All players get priority to cast spells and activate abilities at the following points during the combat phase:
Beginning of combat step (before attackers are declared)
Declare attackers step (after attackers are declared but before blockers are declared)
Declare blockers step (after blockers are declared but before combat damage is dealt)
Combat damage step (after combat damage is dealt)
End of combat step (last chance to use anything referring to attacking or blocking creatures)
