What fire spells would trigger the Slippery Ice effect in Against the Giants?

Question

I've been looking through the Tales from the Yawning Portal book and am thinking about running the Against the Giants adventure; specifically in The Glacial Rift of the Frost Giant Jarl dungeon, it talks about slippery ice on page 181:

Slippery Ice. Fireball spells or other fire effects used in these icy areas will make the footing within the area of effect very slippery. A creature hit by an attack or that moves more than half its speed over slippery ice must succeed on a DC 10 Dexterity (Acrobatics) check or fall prone. For 5 minutes after such magical fire is used, the area will also be filled with fog that renders the area heavily obscured.

So, in short, using fireball can partially melt some ice and make the floor slippery. For spells like fireball, this makes sense to me, since it's an area of effect spell, but when the text says "or other fire effects", would this include spells like fire bolt as well? Or would this be down to me as the DM to arbitrate (for example, I'd rule that create bonfire would cause this effect because it touches the floor, but fire bolt wouldn't because, assuming it hits, it only touches the creature)?

Answer 1

By RAW, any spells that have an area of effect and deal fire damage create slippery ice.

Slippery Ice. Fireball spells or other fire effects used in these icy areas will make the footing within the area of effect very slippery.

The bolded lines are the important qualifications here.
Firebolt and Scorching Ray do not have areas of effect, and they should not create slippery ice.
Burning Hands does have an area of effect, and should create slippery ice.

---

This DM would also allow non-area spells to create slippery ice, if the player chooses to target ice instead of a creature - but that is not explicitly supported by the rules.

Answer 2

Any magical effect that is of the fire element type which targets the ground or has an area effect, should effect Slippery Ice.

Fireball

”… pointing finger to a point you choose …” <— non creature target

”… 20-foot-radius sphere centered on that point …” <— area of effect or ground based

”It ignites flammable objects in the area …” <— magical fire

Using Fireball as mentioned in Slippery Ice, as a template, than any magical effect or spell that replicates these conditions should also cause the same results as Fireball on Slippery Ice.

Flaming Sphere

”A 5-foot-diameter sphere of fire appears in an unoccupied space …” <— area of effect or ground based

”The sphere ignites flammable objects not being worn or carried, …” <— magical fire