Hurling various containers of liquid is a common tactic in dungeon adventures in particular. For game purposes it is necessary to make certain assumptions regarding all such missiles.
Range. The range of all such container missiles is 3”. Beyond 1” is medium, and beyond 2” is long (-2 and -5 “to hit” respectively).
Direct hit. When the die roll indicates the missile has hit, then it is necessary to roll again to see if the container shatters or not - use the item saving throw, “2. Blow, Crushing” — unless special procedures were taken to weaken the container, i.e. the container was specially scored, it is particularly fragile, etc.
Damage occurs only if the container breaks, except with regard to oil which must be alight (flaming) to cause damage.
If oil has been specially prepared by insertion of a rag into the opening of the container (or wrapped around the neck of the container) and set afire prior to hurling, it will burst into flame when the container breaks upon target impact; otherwise, a torch or other means of causing combustion must be brought into contact with the oil.
Splash hits. All creatures within three feet of the impact and breaking point of the container missile must save versus poison or be splashed with the contents of the shattered container.
Misses. If the ”to hit” die roll indicates a miss, roll 1d6 and 1d8.
The d6 indicates the distance in feet the missile was off target.
(If the target was large, simply compute the distance from the appropriate portion of the target, i.e. the character aims at a section of the floor which is 1-foot square, and miss distance is measured from the appropriate edge as explained below.)
The d8 indicates the direction in which the distance in feet of the miss is measured. [Fig. A: Missed Grenade-Like Missile]
At short range, the DM may optionally use d4 to determine distance off target, but then use d8 for long range distance determination.
If the missile is hurled at a plane such as a wall, read long as high, short as low, measuring up the wall and then along the ceiling or down and then along the floor.
Holy/unholy water. All forms of undead, as well as creatures from the lower planes (demons, devils, night hags, night mares, nycadaemons, etc.) are affected by holy water. Paladins, lammasu shedu, ki-rin, and similar creatures of good alignment (or from the upper planes) are affected by unholy water. The liquid causes the affected creature to suffer a burning as if struck by acid. Undead in non-material form cannot be harmed by holy water, i.e. until a ghost takes on material form, it is unaffected, and a vampire in gaseous form cannot be harmed by holy water.
Oil. Flaming oil splashed on a creature burns for 1d3 segments and causes 1 hp damage per segment. A direct hit with flaming oil causes 2d6 the first round and 1d6 the second round before burning out.
If a torch is used to attempt to light spilled oil, use above procedures for misses, as it still could land in the puddle of oil or oil covered area. A lantern should be handled similarly, but also allow it a 2 ft. diameter flaming oil area.
Crossing Flaming Oil. Leaping over a puddle of flaming oil will cause no damage, unless the creature so doing is highly inflammable. Creatures with garments of cloth must save versus “8. Fire, Normal” or have their garments catch fire. Walking through or standing in flaming oil will cause the creature to take 1-6 hit points of damage per melee round.
Poison (special) is dependent upon whether or not the poison is a contact poison or if the container was hurled into the ingestive or respiratory orifice on the target creature. In the latter case, breakage is not necessary if the container was unstoppered; if stoppered check saving throw for breakage using the item saving throw, “3. Blow, Normal”.