How does magic interact with Wizard armor abilities and spells in Dungeon World?

Question

So I recently came across the Mage class in Dungeon World as a freebie given for an optional class pack of three classes. It is supposed to be a replacement for the standard Wizard. Now the relevant parts to my question are:

The Wizard spell Magic Missile:

Projectiles of pure magic spring from your fingers. Deal 2d4 damage to one target.

The Wizard spell Fireball:

You evoke a mighty ball of flame that envelops your target and everyone nearby, inflicting 2d6 damage which ignores armor.

Now, according to the Classes page, subsection Damage:

Add the ignores armor tag if the source of the damage is particularly large or if the damage comes from magic or poison.

These two make me think that Magic Missile would ignore armor because it is magical by nature (magic damage type), and Fireball normally wouldn't ignore armor but for the fact that it explicitly states that it does. This leads me to believe that fire damage is typically subject to reduction from Armor, magical or otherwise, unless stated otherwise.

Now, let's approach the concept of armor as described here:

The Wizard's advanced move Arcane Ward:

As long as you have at least one prepared spell of first level or higher, you have +2 armor.

Compare this to the Mage's advanced move Arcane Ward:

You have +2 armor against magical attacks, and nearby allies have +1 Armor against magical attacks.

Neat! Magical defense. But wait, where does that leave fire damage? Now, to my knowledge, vanilla DW has no special concept of armor vs. magic that the Mage class introduces. It just has "armor". So I see the following possibilities for vanilla DW:

• Magic Missile ignores armor, as armor is ignored by magic damage.

and one of:

• Fire respects armor, as it isn't magic damage. (Unless stated otherwise)
• Fire ignores armor when it "comes from magic", and is emphasized when re-stated. Other fire damage respects armor.

With the concept of armor versus magic as introduced by the Mage, I see the following (renaming "armor versus magic" as "M.Armor"):

• Magic missile respects M.Armor as it is magic damage.

and one of:

• Fire ignores M.Armor as it is fire damage.
• Fire respects M.Armor when it "comes from magic", and ignores it otherwise.
• Fire respects M.Armor when it "comes from magic", and ignores it otherwise, unless, like Fireball it states that it ignores "armor" which we assume applies to both kinds of armor.

It looks like I have 2 × 3 = 6 possible rule combinations to choose from and I'm not sure which is to be honored. Which is the correct combination?

Answer 1

You're getting tripped up my misinterpreting that first quote. Here's the missing context (emphasis mine):

Other sources of damage—like being struck by a chunk of a collapsing tower, or falling into a pit—are left to the GM based on these options:

That line about adding the ignores armor tag is only for that table of damage dice, used by the GM to determine what miscellaneous, undefined sources of damage encountered during play — like falling rocks, traps, lightning-shooting statues, etc. — do to the heroes or to monsters the heroes maneuver into danger. That doesn't have any relevance to the Wizard's spells, nor how armour or magic works in general. It's not “The Rules About How Damage Works”.

So, forget that part entirely and let's start over.

The two principles at work are “what does the move say?” and “what does the fiction demand?”

1. Magic missile does 2d4 damage, as it says. Armour helps against this damage because the damage doesn't have the ignores armor tag or otherwise says the spell does.

2. Fireball does 2d6 damage that ignores armour. (It does this because wearing chainmail isn't going to help someone survive fire. Similarly, if the PCs are taking damage in a burning building, you'd assign damage off that table and give it ignores armor.)

3. The Wizard's Arcane Ward is magical shimmery armour (or something — ask your Wizard how it manifests!). This works against everything (that doesn't have ignores armor) because it's just normal 2 Armor, as it says.

4. The Mage's Arcane Ward provides N Armor against magical attacks only, because it says it does.

   Ignores armor would still apply, unless you all look a the fiction and say “that makes no sense! it should still protect from [the thing]!”, in which case ignores armor doesn't apply. (Because the mechanics to apply to a situation always follow from the fiction of the situation.)

   This Armor would apply against a magical fire attack, because it's a magical attack and it says so. It wouldn't apply against a mundane fire damage because it's not a magical attack.

5. There's no concept of “M.Armor”. It's just normal N Armor, and sometimes the source of that N Armor will say something about what it is/isn't good against.

So these options are right, if we substitute the specific move that we're following in place of the invalid “M.Armor” concept:

• Fire respects the Mage's Arcane Ward when it "comes from magic", and ignores it otherwise.

• Magic missile respects the Mage's Arcane Ward as it is magic damage.

But that second is somewhat redundant because:

• Magic missile respects N Armor as it doesn't have ignores armor or other notes to that effect (unless the N Armor itself says it's ineffective against [magic/Magic Missile specifically/energy/ranged attacks/etc.]).

Answer 2

Nothing ignores armor until stated otherwise

Now, according to the Classes page, subsection Damage:

Add the ignores armor tag if the source of the damage is particularly large or if the damage comes from magic or poison.

The section you quoted from the Classes page has a really, really important context, and it seems you missed it. That part was for GMs. It talks about what kind of damage is dealt when there's no monster move involved (e.g. when an environmental hazard hurts the PC).

The important part that precedes the line is:

Monsters roll damage as listed in their description. Use this damage any time the monster takes direct action to hurt someone, even if they use a method other than their normal attack.

Other sources of damage—like being struck by a chunk of a collapsing tower, or falling into a pit—are left to the GM based on these options:

• It threatens bruises and scrapes at worst: d4 damage
• It’s likely to spill some blood, but nothing horrendous: d6 damage
• It might break some bones: d8 damage
• It could kill a common person: d10 damage

Add the ignores armor tag if the source of the damage is particularly large or if the damage comes from magic or poison.

The rules are clear about when a monster's damage ignores armor: it's written in the monster stats. But what about things that aren't written in rules, like a house fire, or a poisoned plant, or a guillotine slicing down? That's what the passage was talking about. Certainly not a guideline for how damage dealt by PCs works.

Magic Missile doesn't ignore armor because it doesn't say it ignores armor. Fireball ignores armor because it says it ignores armor.

You don't need to (and shouldn't) concern yourself with what "type" of damage it is. DW doesn't make a distinction between "physical" and "magical" and "fire" and whatever damages.

These two make me think that Magic Missile would ignore armor because it is magical by nature (magic damage type), and Fireball normally wouldn't ignore armor but for the fact that it explicitly states that it does. This leads me to believe that fire damage is typically subject to reduction from Armor, magical or otherwise, unless stated otherwise.

Nope. All damage (regardless of source) is subject to armor unless specified otherwise (whether the one stating otherwise is a PC move or the GM).

But what about fire?

There is regular fire (a torch, a bonfire, a fire place, lava, etc.) and then there's magical fire (Fireball, dragon's breath, a fire spell cast by a monster, etc.). Use the fiction and common sense to decide which is which.