My Ifrit chose last session to walk into a flaming sphere cast by our druid in order to melee attack a Troglodyte. The damage of the sphere rolled lower than the Ifrit's fire resistance.
Should I be concerned with his clothes catching fire?
I should add that the DM and the party all thought it was awesome and the DM insta-killed the troglodyte
The spell flaming sphere says
A burning globe of fire rolls in whichever direction you point and burns those it strikes. It moves 30 feet per round. As part of this movement, it can ascend or jump up to 30 feet to strike a target. If it enters a space with a creature, it stops moving for the round and deals 3d6 points of fire damage to that creature, though a successful Reflex save negates that damage. A flaming sphere rolls over barriers less than 4 feet tall. It ignites flammable substances it touches and illuminates the same area as a torch would.
The sphere moves as long as you actively direct it (a move action for you); otherwise, it merely stays at rest and burns. [n.b. What this means is up to the DM] It can be extinguished by any means that would put out a normal fire of its size. The surface of the sphere has a spongy, yielding consistency and so does not cause damage except by its flame. It cannot push aside unwilling creatures or batter down large obstacles. A flaming sphere winks out if it exceeds the spell's range.
By a strict reading--which some may find silly--, the effect created by the spell flaming sphere must enter a creature's square to inflict damage, yet creatures can enter and leave the effect's square freely, without fear of fire damage or catching on fire. The effect's not given an object's hardness nor hp nor nigh-invulnerability a la the spell wall of force, so the effect doesn't impede movement (and would likely say so were the spell to do so as that would increase the spell's combat value significantly).
No, I have no idea how the effect looks, how the effect feels, or how it only burns folks when it's launched at them, but it's been pretty much the same for, like, a decade. I'm just reading the spell.
That's all the spell has to say about the matter. A creature "touched" by a flaming sphere follows the normal procedures for Catching on Fire, as follows:
Characters exposed to burning oil, bonfires, and non-instantaneous magic fires might find their clothes, hair, or equipment on fire. Spells with an instantaneous duration don't normally set a character on fire, since the heat and flame from these come and go in a flash.
Characters at risk of catching fire are allowed a DC 15 Reflex save to avoid this fate. If a character's clothes or hair catch fire, he takes 1d6 points of damage immediately. In each subsequent round, the burning character must make another Reflex saving throw. Failure means he takes another 1d6 points of damage that round. Success means that the fire has gone out—that is, once he succeeds on his saving throw, he's no longer on fire.
A character on fire may automatically extinguish the flames by jumping into enough water to douse himself. If no body of water is at hand, rolling on the ground or smothering the fire with cloaks or the like permits the character another save with a +4 bonus.
Those whose clothes or equipment catch fire must make DC 15 Reflex saves for each item. Flammable items that fail take the same amount of damage as the character.
Pathfinder designer Sean K. Reynolds even says so.1
A creature's possessions are attended objects, therefore sharing their owner's saving throws instead of making their own saving throws. Also, were an ifrit to catch on fire, he has only a 1-in-6 chance of taking 1 point of fire damage per turn, so time is on his side. Finally, were an ifrit to catch on fire, ask the DM if the ifrit's possessions share his resistance to fire 5. I'd argue that such a creature's possessions should or else everyone on the Plane of Fire (a fire-dominant plane) is probably roaming around naked. In fire.
Ask your GM.
Generally, effects that damage characters don't damage the items they're carrying unless some specific rule exception or effect says that they do.
This particular case is unusual, however: Most forms of energy resistance are magical in nature and assumed to apply to an adventurer's gear as much as their bodies, but as you've intuited, your character's energy resistance is an innate property of their biology, and so could be interpreted as maybe not applying to things you wear quite so much. On the other hand, given that your character's biology has a rather fantastic origin, maybe the resistance is magical enough to apply to items of gear worn close to the skin. But then, energy resistance is an extraordinary ability, rather than a supernatural one, so maybe it shouldn't be quite that magical. But extraordinary abilities can break the laws of physics, so maybe it should be able to after all...
...And so on, and so forth. Long story short, this is one of those cases where so many groups will rule it one way or the other that we can't answer the question without asking your GM... And neither can you. But as long as you can trust your GM to make a ruling that's appropriate for your campaign, it should be fine.
By RAW, it isn't possible to walk through a Flaming Sphere, as the spell creates a semi-solid spongy flaming object. However, normal clothes would burn just fine.. if it weren't for a few.. issues.
By RAW, energy damage such as fire, lightning, or cold deals half damage to objects, so hardness is calculated after the damage is divided by two.
Energy Attacks
Energy attacks deal half damage to most objects. Divide the damage by 2 before applying the object's hardness. Some energy types might be particularly effective against certain objects, subject to GM discretion. For example, fire might do full damage against parchment, cloth, and other objects that burn easily. Sonic might do full damage against glass and crystal objects.
This falls under the "objects that might burn easily" so we'll move onto the next step.
Attended (Held/Wielded etc.) Items: Unless the descriptive text for a spell (or attack) specifies otherwise, all items carried or worn by a creature are assumed to survive a magical attack. If a creature rolls a natural 1 on its saving throw against the effect, however, an exposed item is harmed (if the attack can harm objects). Refer to Table: Items Affected by Magical Attacks to determine order in which items are affected. Determine which four objects carried or worn by the creature are most likely to be affected and roll randomly among them. The randomly determined item must make a saving throw against the attack form and take whatever damage the attack dealt. If the selected item is not carried or worn and is not magical, it does not get a saving throw. It simply is dealt the appropriate damage.
If you are the target of a spell or a spell-like ability and you fail your save with a 1, your items become subject to magical damage. Those items are chosen from the list in the order below:
Table: Items Affected by Magical Attacks
Order* Item
1st Shield
2nd Armor
3rd Magic helmet, hat, or headband
4th Item in hand (including weapon, wand, or the like)
5th Magic cloak
6th Stowed or sheathed weapon
7th Magic bracers
8th Magic clothing
9th Magic jewelry (including rings)
10th Anything else
Your vestments aren't magical, so they would fall under the category of "Anything else". If you weren't wearing any items in your other slots, they would be affected long before your clothes would be burned away. However, if you didn't have anything in those other slots.. Your clothes would likely be burnt to a cinder.. on one side anyway, provided all of the prior things were to have been met.
If that was the case, damage would be calculated normally, minus your fire resistance, and any leftover damage would be applied to you, and to your clothing...
