Tidal Wave 5e: Area, Prone, and Fire Interaction
Tidal Wave is a flexible area spell that does more than deal damage. I like being able to shape it to a smaller formation, knock failed targets prone, and extinguish exposed flames across a surprisingly broad area. Its water vanishes immediately, though, so this is a crashing impact rather than a lasting flood.
Tidal Wave 5e — Quick Spell Reference
| Casting Time | 1 action |
|---|---|
| Range | 120 feet |
| Components | V, S, M(a drop of water) |
| Duration | Instantaneous |
| Concentration | No |
| Ritual | No |
| Classes | Druid, Sorcerer, Wizard |
| Source | Elemental Evil Player's Companion, pg. 168 |
How Tidal Wave Works
The caster conjures a wave in an area within 120 feet. That area can be up to 30 feet long, up to 10 feet wide, and up to 10 feet tall. Each dimension is a maximum, so the caster can choose a shorter, narrower, or lower area when that helps avoid allies or fit the battlefield.
Every creature in the chosen area makes a Dexterity saving throw. On a failed save, a creature takes 4d8 bludgeoning damage and falls prone. On a successful save, it takes half damage and remains standing.
The spell affects allies as well as enemies. It has no size restriction on the prone effect, so a Huge or Gargantuan creature can be knocked prone unless one of its own traits or another rule prevents that condition.
Placing the Wave’s Area
Tidal Wave does not use a standard cone, cube, line, or sphere. The caster chooses a rectangular area within the listed maximum dimensions. This makes the spell easier to fit along a rank of enemies or through a narrow space than many fixed-shape bursts.
The whole area must be within the spell’s 120-foot range under the normal area-targeting rules. Walls and total cover can prevent the effect from reaching creatures on the other side. The spell does not say the caster must see the area, but a clear path is still required unless another rule says otherwise.
The description says the wave crashes down on an area and then spreads across the ground. It does not provide rules for suspending a lasting mass of water in midair, carrying creatures, or filling a vertical shaft. If an unusual three-dimensional placement matters, the DM must apply the dimensions and general area rules to the scene.
How Prone Changes the Follow-Up
A creature that fails its save is knocked prone. While prone, it normally crawls at extra movement cost or spends half its speed to stand.
Attack rolls against a prone creature have advantage when the attacker is within 5 feet. Attacks from farther away have disadvantage. Tidal Wave therefore sets up nearby melee allies well, but it can make immediate ranged attacks less accurate until the target stands.
The prone effect occurs only on a failed save. A successful target still takes half the bludgeoning damage but does not fall prone. Tidal Wave does not push creatures, carry them with the water, or leave them restrained.
What Flames Does Tidal Wave Extinguish?
After dealing damage, the water spreads across the ground in every direction. It extinguishes unprotected flames in the wave’s area and within 30 feet of that area, then vanishes.
“Unprotected” is the key limitation. A flame sealed behind a barrier, sheltered in a closed lantern, or otherwise protected may survive depending on the situation. The spell does not define a universal list, so the DM applies the environment.
The text does not limit this sentence to nonmagical flames, but extinguishing a visible flame does not automatically dispel the spell or magic item that created it. A magical effect’s own wording may say whether water can extinguish it or whether the flame reappears. Tidal Wave is not a substitute for Dispel Magic.
This secondary effect reaches beyond the damaging rectangle. A 30-foot margin around the wave can put out torches, campfires, and other exposed flames even when they were not inside the original damage area.
The Water Vanishes Immediately
Tidal Wave is instantaneous. After spreading and extinguishing flames, its water disappears. The spell does not leave:
- standing water;
- difficult terrain;
- a current that moves creatures;
- a flooded room; or
- water that can be collected for later use.
It can still interact with ordinary objects and scenery through the explicit flame-extinguishing effect. Any additional environmental consequence—such as washing loose dust from a floor—is outside the spell’s stated mechanics and belongs to the DM.
Tidal Wave Tactics and Tradeoffs
The adjustable footprint is the spell’s biggest tactical advantage. Shorten the wave to avoid an ally, stretch it along several enemies, or place it where prone targets will be exposed to melee attacks before they can stand.
The spell works especially well when:
- several enemies occupy a narrow formation;
- melee allies can capitalize on prone targets;
- exposed fire is creating a separate hazard; or
- bludgeoning damage is preferable to a commonly resisted element.
It is less attractive when the party relies on ranged attacks, enemies have strong Dexterity saves, or the battlefield needs lasting terrain control. Tidal Wave has no higher-level benefit: a larger slot does not increase its damage, dimensions, prone effect, or fire-extinguishing radius.
Frequently Asked Questions
Does Tidal Wave leave water behind?
No. The water spreads, extinguishes applicable flames, and vanishes.
Does a successful save prevent all damage?
No. A successful Dexterity save halves the bludgeoning damage but prevents the prone effect.
Can Tidal Wave knock a Huge creature prone?
Yes. The spell has no size limit, unless the creature has a trait or other rule that prevents it from becoming prone.
Does Tidal Wave push creatures?
No. It deals damage and can knock creatures prone, but it does not move them.
Can Tidal Wave be upcast?
It can use a higher-level slot, but the spell gains no additional benefit.