Should alchemist fire set someone on fire?

[starwed]

Although the sword's flame itself is not instantaneous, the exposure to such flame caused by an attack is. So I wouldn't let it catch anyone on fire.

 

[frankthedm]

That adds quite a kick to Flaming Sphere... makes a Fire-substituted Acid Arrow quite nasty... and gives the Flaming property rather an edge over Frost and Shock...

-Hyp.

I'd treat the blow from a flaming melee weapon or flaming amuntion's burn you and burn out as instantaneous effects, thus making an energy based thrown [peircing or slashing] weapon a touch more valuable.

Fire subbed acid arrow should be nasty. Though most DMs would probably let the spell be neutralized by Create Water.

Flaming sphere is reflex avoids so that is not that threatening in most situations.

If one is really worried about Catching on fire getting out of hand, try this;

One saves to see if they Caught on fire at the end of their turn.

This way the wise/lucky characters who douse themselves, have an allied cleric douse them with Create Water, get the alchemist fire off themselves, or choose to move away from the wall of fire / burning sphere are safe. While those who don’t have this level of wisdom are punished by divine [actually mundane] fire.

 

[Hypersmurf]

Flaming sphere is reflex avoids so that is not that threatening in most situations.

If you have a good Reflex save, no damage, no problem. If you have a bad Reflex save, not only are you likely to take damage from the spell, but you're likely to catch on fire as well...

-Hyp.

 

[pressedcat]

As per the DMG, if you're exposed to noninstantaneous magical fire, you must make a Reflex save (DC 15) or else catch on fire. Do think this should apply to alchemist fire? Would it only work if the person has flammable clothing, or could I toss it at a scaly monster and watch it burn?

Check the phb page 128, as this says exactly what alchemist's fire does. Ranged touch attack as splash weapon, range increment 10'. Direct hit deals 1d6 fire damage and next round must pass DC15 reflex save or continue to burn. Splash damage of 1 point of fire damage, and probably no secondary effects i'm guessing. As others have said, alchemical fire itself is a flammable oil, so if you get hit by it, you'll be covered in burning oil whether you are wearing flammable material or not.

 

[cmanos]

The alchemist fire burning is not the question. Yes the lizard burns from alchemist fire, but the OP was also asking about "catching on fire" not just being burned by the napalm.

Ah I see....work induced denseness...sorry...

I could see where a scaly creature may not catch fire....or even one with a thick hide, like a rhino or an elephant.