Counterspell basics

[MarkVIIIMarc]

I need my hand held for a moment here.

Lets say the bad guy casts a level 4 spell and I counter with level 3 counterspell.

How does the math work with what I need to roll?

This is probably written out a dozen places so thanks in advance for your patience.

[Longman]

You have to make an ability roll using your spellcasting ability. In the case of your example the DC would be 14. (10+ spell level).

I think this means you make a basic Int, Wis or Cha roll. It's not your spell save DC or your spell attack modifer. It's a basic ability roll with the DC set as 10 plus the spell level.

[MarkVIIIMarc]

Thank you. We might have actually done that right!

In my Bard's case then I roll a D20 for my level 3 Counterspell and add my Charisma modifier. Easy enough.

[PhoenixPhyre]

You have to make an ability roll using your spellcasting ability. In the case of your example the DC would be 14. (10+ spell level).

I think this means you make a basic Int, Wis or Cha roll. It's not your spell save DC or your spell attack modifer. It's a basic ability roll with the DC set as 10 plus the spell level.

Correct. You're rolling 1d20 + MOD (INT/WIS/CHA depending on class) vs 10+spell level. Ties go to the one rolling (you). This gives an about 50/50 chance, assuming a +3 or +4 MOD.

Side note: bards get half their proficiency bonus added to their roll due to jack of all trades, as this is an ability check where proficiency is not normally added.

[Longman]

I've played a wizard with counterspell and that's what we did. I've only GMd a few times, just recently.

If the level you cast counterspell at is equal to the level of the spell being cast, the opponent's spell fails automatically. You only have to roll if the spell level is higher than the slot you are expending.

I am assuming that if the opponent cast a spell with a higher level slot, it would be the slot level that counted for determining the spell's level, and not the original spell level. But I don't have a PHB quote to back that up.

[PhoenixPhyre]

I've played a wizard with counterspell and that's what we did. I've only GMd a few times, just recently.

If the level you cast counterspell at is equal to the level of the spell being cast, the opponent's spell fails automatically. You only have to roll if the spell level is higher than the slot you are expending.

I am assuming that if the opponent cast a spell with a higher level slot, it would be the slot level that counted for determining the spell's level, and not the original spell level. But I don't have a PHB quote to back that up.

Spell level and spell slot level are identical. Spells only have a minimum level--their actual level depends on the slot used.

Counter spell (level X) wins against spell from level X or below automatically and against level X+1 or more with an ability check. Note that you don't get a bonus to the check depending on the slot you use for the counter spell.

[JellyPooga]

Note that you don't get a bonus to the check depending on the slot you use for the counter spell.

That always irritated me. A level 3 Counterspell has the same chance of negating a level 9 spell as a level 8 Counterspell does. It feels like there should be a bonus for using that higher level slot. I get that it's for simplicities sake, but just feels wrong.