Now I'm fairly certain I know the answer to this but I want to make sure before it pops up again in a game.

So in the rules when you deal damage you first assign it and then apply it. If it's "non-combat" damage then the damage is assigned as soon as it is applied and is unable to be interupted by actions.
"

So a few questions:

1. What is "combat damage"? There is no combat phase merely a battlefield phase so is combat all damage dealt during this phase or is it all damage dealt by creatures power when attacking and defending (and/or other abilities like counterstrike and savage)?

2. If damage is dealt by, say, a tactic can toughness negate non combat damage? The confusion here is that toughness doesn't say it's an action but it does say it negates damage when it's applied and yet non-combat damage is applied as soon as it's assigned making me wonder if there's any possibility for toughness to butt in at that point and cancel some of it or not.

The situation that occured was one player using High elves and the other dwarves. The high elf player used "master of the earth" (deal x indirect damage to target player. X is the number of developments you control", the dwarf player being a typical dwarf then just proceeded to divy the damage to his units with toughness negating most if not all of it and thus the question was raised if that was even possible do to the card dealing non-combat damage.

Dark Bunny Lord said:

To keep your words : "It is all damage dealt by creatures power when attacking and defending" (counterstrike / savage are not combat damage).

Dark Bunny Lord said:

Yes, thougness is a constant effect, it's allways effective (you don't even have the choice to use or not thougness) unless a card tell that damage are uncancelable.

Shindulus is correct, except that Counterstrike damage is (unsplittable) combat damage too.

As for non-combat damage, you can think of it as there actually being a step between assigning and applying damage. It's when damage cancellation and redirection happen. You can't take any actions during this step though.

Yes sorry, and they are applied when they are assigned.

Ah thanks for the reply, this was how I figured it functioned, I just wanted to be certain.