Baby's on Fire.

So Adventurers love oil, they like to pour it on the floor, douse things in it, and most of all to throw Molotov cocktail style bombs of it at everything that looks remotely flammable.  All this pyromania should have consequences.  Below is a table for effects of fumbling with flaming oil bombs. The effects are not pleasant, but one or two fumbles will have any surviving characters considering oil based grenades with a bit more circumspection...

1D10 (+ or -)	The table of accidental incineration (Flaming Oil Fumbles) Roll 1D10 and add or subtract the appropriate DEX bonus/penalty
-2	Inferno of Death – Somehow You've managed to coat yourself, and every party member within 10' in a flaming haze of oil doing normal oil damage. That's not the worst though. The flames have caused a chain reaction as any oil bombs in the party's possession explode, unless a save vs. Paralysis is made for each vial. These vials will do 1D6 damage per explosion to the individual carrying them.
-1	Airburst – A perfect throw scatters flaming oil over all party members in 10' of the oil thrower. The oil does normal flaming oil damage.
0	Premature Impact – You've thrown the vial perfectly, assuming you were attempting to drench another party member. Randomly pick another party member and do full oil damage to them for three rounds.
1	It's in Your Armor – Not only did you manage you break the oil over yourself, but you managed to light it after it had soaked into the nooks and crannies of your armor. Take normal oil burn damage for the next three rounds as the trapped fire takes longer to burn.
2	Self Immolation – Your doused in flaming oil. You're on fire and it hurts. Take normal oil damage.
3	Friendly Fire – You've doused 1D4-1 party members in flaming oil for normal oil damage.
4	Splash Damage – It wasn't a clean hit, but you've splashed 1d4-1 party members (including yourself) with flaming oil. All will take 1D4 points of damage.
5	Ceiling of Pain – Now the Ceiling is covered in flaming dripping oil. Everyone in a 10' radius must save vs. paralysis or take 1D6 points of damage for the next two rounds. If outdoors treat as a roll of (-1).
6	Hot Foot – You just dropped a flaming bottle of oil on your foot. Take 1D4 damage and roll a Save vs. Paralysis to hop away before taking an additional 1D8 next round. In any event you're jumping around with a flaming foot, unable to act for 1D4 rounds.
7	Fails to Light – The bottle clash against the ceiling, a branch or your fighter pal's helm and douses 1D4-1 party members in oil. Luckily it was unlit, and your allies are simply soaked in highly flammable oil.
8	Covered in Oil – You managed to break the bottle over your head and are now soaked in oil. It's not on fire, but it could easily get that way.
9	No Retreat – Whoops, slippery bottle. The oil lands directly behind your party and blocks any hope of retreat until it burns out in two rounds.
10	A Perfect Disruption – Arcing with perfect aim the oil bursts between the shield walls and creates a flaming barrier that prevents melee combat between the belligerents for two rounds. Missiles may still be used,
11	Drops in Eyes – The oil flew off fine, despite missing embarrassingly, but a big splash of unlit oil ends up in your eyes. You'll be blind for 1D6 rounds, attack at -4 each round or rub your eyes and save vs. Paralysis to get the painfully stinging junk out.
12	That's not Oil – You threw something else by accident, GM decides what else in your pack was hurled, and its effects, but hobgoblins are nonplussed by holy water, and that potion of heroism you were saving, well now it's on the shattered on the floor.
13	Stoppered Vial – In the excitement you forgot to light or unstopper the darn thing and it bounces off a target landing unbroken on the floor. Maybe you can pick up it later.