Declaring the intent to counterspell or delaying actions makes me uneasy: another round lost, more time lost at the table. I think for spell duels what we need is a kind of *bullet time* where all the spells go off at the same time, all of them cancelling each other as far as possible.
Thus, the basic rule is this: if you haven’t acted this round and a spell it being cast at you, you can use your action to react with any spell in your repertoire, aiming to counterspell. The side with initiative declares first.
Consequently, if you have already cast a spell this round and none of your opponents decided to counterspell, then they cannot cast a spell at you this round because your spells would have cancelled as far as possible. If you didn’t cast a spell, or if they are attacking you with other means, no problem.
Effectively, all the spell casting happens in the same moment.
Examples:
When somebody casts *magic missile* at you and you haven’t acted yet, cast *shield* to defend yourself. This is a perfect counterspell.
When somebody casts *fireball* at you and you haven’t acted yet, cast *lightning bolt* to defend yourself. Both sides roll damage and only the difference gets applied to the loser. This works even when there are multiple people attacking each other. The winner gets to decide how effects are distributed amongst multiple losers.
In this case we’re assuming that all damage dealing spells are somewhat alike. Over time you’ll build a collection of rulings as to which effects can cancel each other like that.
Whenever spell effects cannot be compared directly, the simplest solution would be to have both sides roll their saving throws, if any. When both make their saves, nothing happens. When only one side fails their save, they are affected by the other’s spell. If both sides fail their saving throws, the spell of the higher circle wins: *hold person* (2nd circle) beats *charm person* (1st circle) if both sides fail their saving throws.
Similarly, if one side casts *hold person* and the other side casts *fireball*, both need to roll a save — one to avoid being held, the other for half damage. If both casters fail their saves, *fireball* (3rd circle) beats *hold person* (2nd circle).
And finally, if one side casts *sleep* and their victim can be affected, the other side is simply considered to have already failed their save.
This also means that it can be disadvantageous to attack with weaker spells because the counterspell might simply cancel whatever you threw at your opponent and thus you effectively gave away the initiative.
#RPG #Old School #Halberds and Helmets