These spells were going to be invented by an ocean, wave and storm magus in a recent game hat I’ve had to exit.
Personal Ward Against Iron
Rego Terram 20, R: Personal, D: Diameter, T: Individual
The caster is warded against iron, which is deflected away automatically when it approaches their personal space.
(Base 5 to ward against dirt, +1 Diameter, +2 iron)
Swim Safely Among the Ice Flows
Muto Aquam / Ignem 5, R: Touch, D: Concentration, T: Special
The water immediately around the caster is warmed so it will no longer chill people or objects.
(Base 2, +1 Touch, +1 Concentration, +1 Unusual target surrounding the caster)
A few spells for a Magus with a strong focus in Aquam, a major virtue of Elemental Magic, and also a magical Vulnerability to Iron. On first look a boiling oil spell seems to need an additional requisite, however not for the elemental magus, who can ignore the effect of the Ignem requisite in the spell calculations. Harder for most magi to cast so they probably wouldn’t bother, but not for all magi.
I think these spells are justified as a CrAq spell could create water, optionally boiling water with an Ignem requisite at the same Base 4 as the base to boil water is also CrIg Base 4. Creating normal oil is equivalent to water as shown in the Creeping Oil spell in the Ars Magica book uses a Base 3.
I have also assumed that the example spells like Creeping Oil and the other Aquam spells show that boiling oil needs the Ignem requisite and a minimum level equivalent to CrIg4, instead of reducing the amount of oil produced downward by one more step in the base guidelines. That would make it similar to a strong acid and other highly corrosive Aquam or Terram based materials.
Jet of Bubbling Oil
Creo Aquam / Ignem 15, R: Voice, D: Momentary, T: Individual
Projects a large splash of boiling oil on a victim inflicting +12 damage.
(Base 4 “to create a liquid in an unnatural shape”, +2 Voice, +1 boiling liquid)
The Base amount created for oil is still a very large volume relative to the size of a human victim, so it is quite likely to cover a significant part of the victim which doubles the base damage of boiling oil from +6 to +12.
I initially started to consider allowing an athletics check to avoid some damage however the same should then apply to CrIg effects – and that just isn’t so. This is a conjured material so it can be automatically targeted as desired, and is resisted my MR or Parma Magica – again, just like Ignem spells.
A key risk for Aquam spells which isn’t really considered in the spell mechanics is the splash effects. A spray of oil will be potentially harmful to everything around it, and while that is not reflected in the rules in many places the same is true for many forms of direct damage.
Then moving on to more dangerous spells.
Bathed in Boiling Oil
Creo Aquam / Ignem 20, R: Voice, D: Momentary, T: Individual
Conjures a globe of boiling oil enveloping the victim which inflicts +24 damage.
(Base 4 “to create a liquid in an unnatural shape”, +2 Voice, +1 size, +1 boiling liquid)
This effect combines the Mighty Torrent of Water knockback and force with a pond sized volume of boiling oil – in the description the damage amounts are kept separate both to demonstrate the different source of damage and so that characters with a resistance to heat damage might reduce the effect somewhat.
Might Torrent of Boiling Oil
Creo Aquam / Ignem 30, R: Voice, D: Momentary, T: Individual
A wave of molten oil over three feet wide appears and violently strikes the victim, inflicting +10 damage from the force of the wave, and must make a Strength + Size check vs 9 or be knocked backward. Additionally the furious oil burns the victim for +18 damage as it covers them and likely parts of the surrounding area.
(Base 10, +2 Voice, +1 size, +1 boiling liquid)
Creo Aquam / Rego Ignem 30, R: Voice, D: Diameter, T: Individual
The caster conjures and directs the movement of a large upright wave of boiling oil, allowing them to wash the oil over objects and foes alike. This spell conjures a wave equivalent to a pool 5 paces wide and two paces deep. The oil inflicts +6 damage to those splashed by a small amount, +12 damage for a limb, +18 for half a person, or +24 damage to anyone fully covered or attempting to move through the wave. The spell sustains the oil at boiling point and maintains its placement without concentration, however the cast must concentrate to direct the wave which moves a jogging pace across the ground.
(Base 4 to create a liquid in an unnatural shape, +2 Voice, +1 Diameter, +1 Rego, +1 size, +1 boiling liquid)
Boiling Wave of the Siege
Creo Aquam / Rego Ignem 40, R: Voice, D: Diameter, T: Individual
The caster conjures and directs the movement of a large wave of boiling oil, identical to the Boiling Wave, enlarged to a pool equivalent to 45 paces wide and 7 paces deep. Enveloping large areas is relatively simple.
(Base 4 to create a liquid in an unnatural shape, +2 Voice, +1 Diameter, +1 Rego, +3 size, +1 boiling liquid)
Refuge Upon the Waves
Muto Aquam / Terram 20, R: Touch, D: Sun, T: Part
The targeted water is shaped into a boat which is solid enough to rest within and floats upon the surface of the surrounding water. The boat is six paces long, three across and two paces deep.
(Base 4 to transform into highly unnatural water, +1 Touch, +2 Sun, +1 Part)
Footsteps Across the Narrow Sea
Muto Aquam / Terram 20, R: Personal, D: Sun, T: Part
Water beneath the caster is changed to a solid pathway which the caster may walk upon. Particularly choppy water will require a Dexterity + Athletics check to stay upright.
(Base 4, +2 Sun, +1 Part, +1 unusual effect)
Rego Aquam 15, R: Touch, D: Concentration, T: Individual
The water surrounding a person or object moves as a rapid current, which allows the caster to move it quickly through the water as they please. Note that a breathing target may have difficultly swimming and breathing normally whilst surrounded by the churning water.
(Base 5 “to control water in violent way”, +1 Touch, +1 Concentration)
Uplift, Rinse, Spray
Rego Aquam 25, R: Sight, D: Concentration, T: Part
Water is moved as directed by the caster in a quick and graceful manner, although not quickly enough to inflict damage. Target: Part allows the water to be drawn from an existing source for as long as the cast concentrates.
(Base 4, +3 Sight, +1 Concentration, +1 Part)
The Spilled Barrel
Creo Aquam 10, R: Touch, D: Sun, T: Individual
Covers the ground in water.
(Base 3, +1 Touch, +2 Sun)
An Unwanted Dunking
Creo Aquam 15, R: Voice, D: Diameter, T: Individual
Conjures a five pace diameter pool of water at a place within range which then falls to the ground. Everything beneath is soaked.
(Base 4, +2 Voice, +1 Diameter)