Underwater spell casting

Rules Questions

Grand Lodge

Pathfinder Adventure Path Subscriber

Can anyone tell me which book I'll find the effects of underwater spell casting in please? (Can fire spells be cast, does lighting become a "ball", things like that.)


Core Rule Book

Or check SRD under Environment for Aquatic Terrain and Underwater Combat.

Grand Lodge

Pathfinder Adventure Path Subscriber

Thanks, read that now. Any ideas on lightning? :)

I've struggled with that too. I'm always tempted to turn any lightning effect into a spread centered on the caster that does the normal damage of the spell (or maybe a little less) to anyone caught in the area. Including the caster.

Electric Eels can deliver a shock to a single fish several meters away without harming anything else around it. I see no reason a magic bolt of electricity couldn't do the same.

For underwater adventuring rules (exhaustive and complete) you want the Cerulean Seas Campaign setting. It's the sourcebook for all things underwater and a full-treatment of everything you need to run an adventure there. There's a very good treatment on how spells work differently in an aquatic environment as well other parts of combat.

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To cover your specific questions, general rules for non-aquatic species casting spells underwater are covered in the core rulebook. For more details on how things change under the water, I'll quote the Cerulean Seas preamble for the magic of the seas section.

Cerulean Seas Campaign Setting Magic Section Preamble wrote:

While the spells from the Pathfinder Roleplaying Game Core Rulebook that were not altered here were designed for a land campaign involving humanoid characters with hands and feet, it is not too hard to extrapolate an underwater effect for them, and fins, flippers, and tentacles can easily replace hands and feet in the description. Likewise, if a spell refers to walking and running, it now refers to swimming and diving. All aquatic races can cast spells underwater without the need for a concentration check (as is called for non-aquatic races to cast spells underwater).

Other Notable Exceptions
Invisibility Effects: In the Pathfinder Roleplaying Game Core Rulebook, invisibility spells cause a bubble-like effect underwater, rendering the invisible creature partially visible. Aquatic races have since compensated for this effect. Invisibility works normally when cast
underwater, causing the subject to be visually undetectable by normal means. However, when a subject becomes invisible underwater and then moves to the surface, he appears as a watery shape, much like if invisibility was cast above the water and the subject went below. In essence, invisibility specifically refers to the medium it is cast in. While outside of that medium, the subject is granted concealment (20% miss chance). In any case, invisibility is somewhat less effective in an underwater environment, because a good percentage of creatures can detect you without using sight.

Etherealness, Freedom of Movement, and Incorporeal Effects: While subject to these effects, creatures are immune to the effects of
pressure and drag. In addition they maintain zero buoyancy, regardless of their load. As soon as the effect wears off, so does the immunity.

Cold Energy Effects: At depths of fewer than 300 feet, spells that create extreme cold also form potentially damaging ice crystals. Below 300 feet, the pressure is too great to form ice from water.

Fire Energy Effects: Instead of fire as an energy type, it is replaced by Steam. Steam appears as a billowing white cloud that creates a curtain of steam bubbles above it. Hot water has a shimmering diffraction effect on water that is as obscuring as smoke is on land. Steam-based spells cannot catch flammable objects on fire like fire-based spells can, though most aquatic objects could not be considered flammable in any case.

Electricity Energy Effects: Electricity is a common element under the ocean, though it assumes a much different form than it does on land. On land, electricity is known for its bright crackling arcs of lightning. While these are not unheard of in an undersea setting, the fact is that the oceans rarely get hit with lightning. The surface water of the sea does not typically heat up enough to cause the positive charge needed for lightning to occur. When it does occur, it is almost always near shore. After lightning hits the water, it disperses in a great and terrible electrical sphere that is as deadly as it is undetectable. The picture this paints of underwater electricity is more commonly exemplified by the electric eel. Instead of flashy and sweeping arcs, electricity is known for its invisible spheres of damage. The lightning bolt of the sea, electrical surge, is actually a small sphere of electricity that travels towards the target, rather than a continuous arc. Aside from a trail of dead plankton and the occasional bubble of steam, this effect is relatively quiet and undetectable compared to its drylander equivalent.

Levitation: This spell essentially takes over the buoyancy of a creature or object, superseding any forces natural buoyancy exerts. Creatures can swim and fight normally while under the effects of this spell while below the water. They can float up, sink down, or remain level all at the given rate of the spell. However, once above the water,
levitation works as written.

Other Flying Effects: Under the water, effects that let you fly give you 0 buoyancy regardless of load. One-quarter of the fly speed conferred by magic can be applied to the subject’s base swim speed with a successful Fly check, DC 15. Subjects cannot add this speed in areas with a current moving faster than 30 feet, or when they are disoriented.

Prone Effects: Any effect that renders a creature prone, instead renders a creature disoriented.

Also, for combat, here's what it has

Cerulean Seas Campaign Setting Combat Section wrote:

Aquatic Combat

Combat works essentially the same under the water as it does on land, with a few notable exceptions. While all land moving maneuvers such as a five-foot step and attacks of opportunity apply to swimming, other maneuvers have slightly different effects. The most notable change is that the prone condition is obsolete underwater. This condition has been replaced by the “disoriented” condition. When an effect would normally elicit a prone position, the effect causes the character to be disoriented instead.

Disoriented (condition): The character has lost track of which way is up and therefore cannot account for buoyancy and is terribly off-balance. In addition to not being able to sacrifice swim speed to battle the effects of buoyancy or water currents, the character gains a -4 penalty on melee attack rolls and cannot use any ranged weapon. A spinning and flopping disoriented defender gains a +4 bonus to Armor Class against ranged attacks, but takes a -4 penalty to AC against melee attacks. Righting oneself is a move-equivalent action that provokes an attack of opportunity.

A character can, as a free action, choose to flop around so erratically that he causes himself to become disoriented. This would be a good way to avoid ranged attacks, as the target becomes harder to hit as its movement becomes chaotic and unpredictable.

Adjacent Squares: Underwater combat happens in three dimensions. Therefore, there are many more places from which one can be attacked. On land, there are usually 8 adjacent squares; right, left, front,
back, and the four diagonals. In the sea, there are potentially 26 adjacent squares; the normal eight plus a plane of nine squares both above and below each Medium or Small-sized individual. This also
means that an individual threatens all of these squares because they are considered adjacent squares. Swimming creatures can make a 5-foot step into any adjacent square as well, including straight up.

It makes perfect sense for a combatant to back itself against a rock, move to the surface, or swim to the bottom in an effort to eliminate some of these potential openings for attack.

Unfortunately, if these squares aren’t completely occupied by something else, they are considered adjacent. Creatures at the surface of the water could be potentially attacked from the plane above, but only by creatures that can fly or move on the surface of the water.

Weapons: While terrestrial races have a lot of issues using weapons underwater, aquatic races do not suffer the same penalties. Aquatic races not only design their weapons aquadynamically, but they train to use them under the water as well; learning how to overcome the forces of buoyancy and drag to get the greatest striking and damage potential. As long as the character is using weapons tailored for undersea combat (detailed in Chapter 5), using natural weapons or striking unarmed, the character suffers no penalties to hit or damage for being under water, regardless of the type of weapon.

Plunge Weapons: There are no thrown weapons that have any significant range in the Cerulean seas campaign setting. However, some weapons can be plunged towards opponents. Plunged weapons are in fact propelled at full speed in the direction of their buoyancy. To be used effectively, the character must be either directly above (for negatively buoyant weapons) or directly below (for positively buoyant weapons) their intended target. The plunge weapon has a range increment, much like a thrown weapon, but is often slightly longer than their thrown counterparts.

In currents moving 50 feet or faster, a plunge weapon with positive buoyancy can be launched in the direction of the current, though its range increments are cut in half. Currents also affect plunge weapons that are not moving in the direction of the current, conferring a -2 penalty to hit for every 5 feet of speed that the current is moving, and the range increment is halved. Plunge weapons cannot be launched in a current that is moving 50 feet or greater, unless it is in the same direction of that current.

Plunge weapons are typically made to be either positively buoyant or negatively buoyant and come with attachments that can reverse the polarity of their buoyancy. These attachments are typically one buoyancy unit (bu.) greater than the bu. of the weapon in the opposite polarity of the weapon.

For example, a harpoon that exhibits -6 bu. has an attachment that exhibits 7 bu. to enable it to be launched from below. Adding these attachments takes a move equivalent action.

Masterwork plunge weapons can be adjusted without an attachment, but still require a move equivalent action to reverse their polarity (usually a twisting or pumping action to increase or release pressure inside the core of the weapon, thus changing its density.)

Splash Weapons: These work essentially the same as they do on land, except that they generally do not discharge unless they land in a square with a solid object. In an aquatic setting, it is highly plausible that missing with a splash weapon causes it to land in a square of empty water. Consequently, the splash weapon hangs motionless (if it is a zero buoyancy item), floats, or sinks until someone or something hits it moving at a speed of at least 50 feet. If it floats or sinks for more than 5 rounds and then hits an object, creature, or surface it detonates into that square. Otherwise, it just rests against that object or surface undetonated.

If released into a water current that pulls it faster than buoyancy, it moves in the direction of the current, and could potentially hit any directly upstream object or creature that is not moving with the current. If it is moving at least 50 feet per round, it will discharge.

In addition, the splash effect happens in three dimensions. After missing with a splash weapon, before rolling 1d8 to determine the misdirection of the throw, roll a 1d3. A roll of 1 indicates that the weapon lands in the plane five feet above the target, a roll of 2 indicates that it is in the same plane, and a roll of 3 dictates that it has landed in the plane 5 feet below the intended target. If it is in the same plane as the target, apply the 1d8 directional roll accordingly (where 1 is directly in front of the target, moving clockwise). If it is in a different plane, roll a 1d10 instead, with rolls of 1 through 8 be applied in the same way, and rolls of 9 or 10 referring to squares directly above or below the target, depending on the plane on which it lands. If there is a solid surface above or below the target, any result that would have the splash weapon enter those
areas cause it to instead detonate in the same plane as the target, according to the roll of the 1d8.

Large and larger targets typically take up more than one plane. In such cases, always assume that the center of the creature is the intended target and make attacks accordingly. With this in mind, it is possible to miss the center of a large target and still hit its top or bottom, though this would not be considered a direct hit. Regardless of the size of the target, a missed splash attack only has a chance of landing in a cube of 27 five-foot squares, where the exact center square of the cube is the center of the target.

Aquatically launched splash weapons and the effects associated with splash weapons will not extend beyond the surface of the water due to surface tension. While the surface of the water alone will not detonate a splash weapon, any result that would have the splash weapon or the effects of a splash weapon enter an area beyond the water’s surface, instead applies to the plane directly below it.

Splash weapon containers in an aquatic setting are usually not made of glass or ceramic as they are in a terrestrial setting. Instead, the splash weapon is usually contained in a thin membranous material, much like a water balloon. This membrane is typically made of animal intestine, seaweed, or the bodies of common invertebrates such as jelly fish, sea slugs, and sea anemones.

I'm running Skulls & Shackles. Underwater shouldn't impact energy spells other than fire (in which case it simply turns it to steam).

And for one more thing, here's the aquatic equivalent of lightning bolt

Electric Surge wrote:


School evocation [electricity]; Level sorcerer/wizard 3, witch 3
Casting Time 1 standard action
Components V, S, M (a few scales from an electric eel)
Range 120 ft.
Area 120-ft. line
Duration instantaneous
Saving Throw Reflex half; Spell Resistance yes

You release a pulse of electrical energy that deals 1d6 points of
electricity damage per caster level (maximum 10d6) to each
creature within its area. The pulse begins at your fingertips, and
moves forward at lightning speed to the end of the area. While
the end effect is the same as its surface equivalent "lightning
bolt," the source of the damage is basically a five foot diameter
sphere of electricity traveling through the extent of the area very
quickly rather than a continuous stream of electrical energy
arcing from the caster to the target.

The electrical surge can melt metals with a low melting point,
such as lead, gold, copper, silver, or bronze. If the damage caused
to an interposing barrier shatters or breaks through it, the pulse
may continue beyond the barrier if the spell's range permits;
otherwise, it stops at the barrier just as any other spell effect does.
Out of water, this spell has a range of touch, with an area of
"creature touched".

Grand Lodge

Pathfinder Adventure Path Subscriber

Nice summary, thank you.

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