23
\$\begingroup\$

This situation happened in the last session I ran:

Evil wizard casts a Wall of Fire across the middle of a room. She's on one side, and the PCs are on the other. The party wizard decides he's going to cast a Cone of Cold through the Wall of Fire. My gut tells me this shouldn't work, but there's nothing in the rules that says it doesn't. People/objects can pass through the Wall of Fire (and take a bunch of damage doing so), so I guess a spell could also pass through?

Can a Cone of Cold pass through a Wall of Fire?

\$\endgroup\$
  • \$\begingroup\$ Note that the tag [rules-as-written] doesn't exist for questions just asking what the written rules are. (Confusing, I know.) For a question about what the rules are, the tag to use is the one named after the rules being asked about — in this case, [dnd-5e]. \$\endgroup\$ – SevenSidedDie Nov 9 '16 at 17:49
40
\$\begingroup\$

Yes.

There is no written rule that says that area of effect magical effects block other area of effect magics. However, the two spells, by the rules, also don't interact in any way. The best your party wizard could hope for is to hit the evil wizard with the Cone of Cold and end his concentration on Wall of Fire.

\$\endgroup\$
  • 6
    \$\begingroup\$ I guess this is the crux of it, D&D 5e doesn't have any RAW for spell effects interacting with each other. Other than making up some house rules, all spell effects happen regardless of the quirky rule situations that come up like this one. \$\endgroup\$ – fiend Nov 9 '16 at 16:43
15
\$\begingroup\$

Nothing stops the cone

There is nothing in the rules that would disallow this. However, it does sound like a great opportunity to grant advantage on the save to resist the cone of cold.

DMG 239:

Consider granting advantage when:

  • Some aspect of the environment contributes to the character's chance of success.

Fire in the way of cold sounds like an environmental factor to me!

\$\endgroup\$
  • 1
    \$\begingroup\$ Very nice balanced, RAW answer. \$\endgroup\$ – Protonflux Nov 10 '16 at 17:48
12
\$\begingroup\$

RAW I think the Cone passes through just like any other effect would, but...

In cases like this with clearly opposing spell effects I treat them as opposing Dispel Magics (As it is unclear if the Wall of Fire should block the Cone of Cold or if the Cone of Cold would blast a breach in the Wall of Fire or even put it out completely.)

On Dispel Magic it says that for spells above 3rd level you should do an ability check with the casters spellcasting ability versus the target spells level + 10.

If you invert this check and make it opposing it becomes:

A casters spellcasting ability check + spell level versus the same for the other casters ability and the opposing spells level.

The spell that wins cancels the effects of the other, at least for that round.

I would judge that if the Wall wins, the Cone is blocked. If the Cone wins it passes through and nullifies the wall at that point for a round. If the Cone wins with a lot (like 10) the Wall is actually dispelled.

\$\endgroup\$
  • 5
    \$\begingroup\$ I agree with what you're saying in spirit, but in the RAW, the damage types don't actually list which types are opposed to which other types. Cold and Fire seems obvious, but what is the opposite of acid? Lightning? It's a pretty big grey area. :/ \$\endgroup\$ – fiend Nov 9 '16 at 16:40
  • 9
    \$\begingroup\$ I would judge it less on opposing damage types and more on opposing effects. Consider a case where two wizards attempt to move the same item with Mage Hand or if someone casts Command on a Dominated target etc. \$\endgroup\$ – Sesdun Nov 9 '16 at 17:19
  • 2
    \$\begingroup\$ At the same time, this could become complicated. Would a gust of wind increase the effects of the wall of fire by giving the fire more to burn on? \$\endgroup\$ – Alexis Wilke Nov 9 '16 at 18:26
  • 4
    \$\begingroup\$ No, it is a magical fire. The wall of fire would burn just fine on a stone floor and needs no fuel. Also I don't like to mix real world chemistry into fantasy (fire is an element, not a chemical reaction). But yes it becomes a bit more complicated with spell interactions like this but that is what the DM is for in my opinion and playstyle, to give the world and rules life. If a player wanted to push the flames towards someone close by but not in range of them with a Gust of Wind I might allow it (because I like that kind of thing from players), but that is not a case of opposing spells. \$\endgroup\$ – Sesdun Nov 9 '16 at 18:39
  • 2
    \$\begingroup\$ I think that in 5E, this kind of thinking is more encouraged than in previous versions. Notably 3E and 4E explicitly stated that area effect spells did not interact in this way. But in 5E, the DM is encouraged to think beyond mechanics of areas, damage etc, and smart interactions between spell effects could be a cool addition to a game for any DM who is willing to tackle the many possible rulings and player requests that this could bring up \$\endgroup\$ – Neil Slater Nov 9 '16 at 22:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.