Dragon Encounters

How to Use: Keeping the Overwhelming Elemental in Check

The water elemental’s stat block has a problem: its special attack is overwhelmingly strong.

When it uses Water-Surge/Whelm and captures a PC, that PC is basically helpless. Then it just dives back into the water. With 90 feet of movement, the other players have no hope of catching it — the PC is as good as dead. And once it’s done, the elemental can come right back and grab another. Even a level 20 party might not be able to stop it once it’s underwater with a hostage (unless they blow up the whole lake).

So how do we stop the elemental from using that strategy? One idea is to say its master told it to stay up front and fight. But let’s be honest — that’s kind of boring.

Combat Encounter 1: Treasure Below Deck (difficulty 6)

The players are aboard a ship when a water elemental erupts from the sea — but instead of attacking randomly, it has a goal: a treasure chest hidden somewhere on board.

The elemental has been ordered to retrieve the chest. It won’t waste time dragging captives back to the lake, because it knows it has to get through the players to reach its target. While it could phase through them or ignore them, it’s smart enough to realize that unless it clears the path now, it won’t be able to carry the chest out later.

The players have to stop the elemental before it gets the chest… or risk a chase scene across the sinking remains of the ship.

Combat Encounter 2: Liquid Logic, Solid Problems (Difficulty 7)

In this encounter, the water elemental doesn’t fully understand just how… solid human bodies are. It grapples a PC, then flows through fences, holes, or narrow gaps — and the captive gets battered loose along the way. Each time, the player ends up prone, possibly in a hard-to-reach or inconvenient location (e.g., wedged between cargo, or sprawled across slick planks).

To keep the damage reasonable, you can fold this impact into the damage from the grapple itself — avoiding double-dipping or complicated homebrew.

While the elemental won’t keep its captives long, its chaotic movement more than makes up for it. It pops up from unexpected spots, forcing the players to stay alert. Combine this with other problems — hostile enemies, crashing waves, storm winds, or leaks springing open from the elemental’s violent movements — and your players will be scrambling just to keep the ship afloat.

Combat Encounter 3: Fish in a Net (difficulty 7)

The ceiling is rigged with large hanging nets. When the elemental grapples someone and flows upward through one, it passes through easily — but the net folds shut around the captive and traps them. If you want to be extra cruel, some of the nets are rigged to hoist their contents up to the ceiling once a weight is detected.

Now, getting captured by the elemental doesn’t mean drowning — but it does mean being helpless, dangling above the battlefield.

DM note: Decide how these nets affect line of sight. A single net probably doesn’t block vision. Three in a row almost certainly do. Two? Use your judgment based on how tight or loose the weave is.

Combat Encounter 4: A Transparent Defense (difficulty 7)

If you use the water elemental as a bodyguard for a boss, it’s worth remembering two key traits: it’s Large, and it’s transparent.

That means the elemental can stretch from floor to ceiling in smaller rooms — but some spells might still be cast through it. As long as the spell isn’t a projectile (like Magic Missile or Fireball), line of effect may still be intact. This opens up creative options if the boss has magic.

For best effect, place the boss in a narrow space with the elemental blocking the only approach.

Combat Encounter 5: Catch the Screaming VIP (difficulty 6)

The water elemental hasn’t been sent to kill — it’s been sent to capture a specific NPC. That NPC is now sprinting across the deck, ducking behind crates, slipping on wet planks, and generally making a scene.

The elemental, of course, doesn’t care about obstacles. It flows straight through bars, between barrels, and around corners — all while the players are forced to run around the same terrain.

To give the players a fighting chance, consider placing a wand nearby that deals cold damage, which will slow down the elemental. But it only has a few charges, so they’ll need to use it wisely.

Want to raise the stakes? Don’t just send one elemental. Two will make it harder to stall them with cold spells, forcing them to also use clever movement. One can circle around while the other presses forward, cornering the NPC unless the players intervene fast.

For more encounters where the enemy ignores terrain while the players struggle to keep up, see Earth Elemental

Wild Water Elemental

A water elemental without orders will eventually drift toward the nearest body of water. If it reaches a river, it will follow it — always moving — until it finds a lake. Once it does, it settles in, assuming this is the whole world. It doesn’t know that oceans exist, or that water flows elsewhere.

But trouble begins when people try to redirect or dam that water. Whether for irrigation, millwork, or simple expansion, the elemental perceives this as an attack — a violation of its domain and an enslavement of its waters.

It responds the only way it can: it tries to tear the dam apart.

Combat Encounter 6: Three Cracks Dam (difficulty 8)

The elemental isn’t focused on the players — it’s focused on the dam. This encounter is less about slaying a monster and more about racing to stop it before disaster hits.

The elemental doesn’t stay still. It slips in and out of gaps in the structure, attacking from new angles and constantly changing position. Melee characters may need to climb ropes or rig makeshift harnesses to reach different parts of the dam, or lie in wait and try to predict where the elemental will surface next.

Ranged fighters and spellcasters have more freedom of movement, but they face a different risk: collateral damage. An ill-placed Fireball or slingstone might finish the elemental’s job for it.

For an easy version of this encounter, the elemental slams the wall directly with its attacks. For a harder version, have it weaken the structure by slipping in and out of cracks — widening the gaps and letting water do the work. That frees it up to strike at the players instead. You can change mid-battle, if needed.

Characters standing on the dam risk being washed off as water begins flowing through the breaches. Meanwhile, characters positioned at the foot of the dam may avoid direct damage — but once the wall gives way, they’ll be in the path of a flash flood.

Variations:

If you want to make this encounter both harder and more traditional, add a few low-level flying enemies to harass the players. If they’re intelligent, they might be waiting to pick off the corpses once the dam collapses. If not, they’re simply territorial — and the players have gotten too close to their nesting grounds.

To make the encounter easier, consider giving the players an NPC ally with a wand that helps hold the wall. Stone Shape is an excellent choice: it’s powerful but limited by its touch range, meaning the wizard will need to get close to the breach to use it effectively — adding tension and risk without removing player agency.

A Dead Water Elemental

Logically, when a water elemental dies, it should collapse into a pool of water. Depending on where this happens, the aftermath could matter: a smooth floor might become slick, or packed dirt might turn into mud, making the terrain harder to traverse.

That said, D&D often ignores what happens to bodies after death. By the same logic, a Huge or Gargantuan monster should leave a massive obstacle in its wake — and yet we rarely treat them that way. It’s really up to you whether you want to make an exception in this case.

If you do, it can be a fun way to extend the elemental’s influence beyond death — even if just as a minor hazard or tactical complication.

Summary: Six Water Elemental Ideas

The water elemental’s grapple ability is extremely powerful. Logically, it should use it to grab players one by one and drag them to the bottom of the lake or ocean. Since the players can’t realistically counter that, the elemental needs other objectives or limitations to keep the encounter fun and fair.

Here are six ways to use it effectively:

1. Goal-Driven Mayhem: The elemental can cause havoc while its summoners attempt to retrieve a treasure, free a prisoner, or accomplish another goal. Its priority is to move past the players, not defeat them outright.

2. Tight Spaces, Slippery Foe: With its fluid form, the elemental can slip through tight spaces, creating chaos on a ship or inside a structure full of small compartments. It’s hard to pin down when it’s always reappearing elsewhere.

3. Entanglement by Design: Have the elemental grapple a PC and then flow through nets or rigging, leaving the unfortunate captive entangled or dangling. The elemental passes through easily — the players do not.

4. Transparent Tactics: Because it’s transparent, many spells (as long as they don’t rely on projectiles) should be able to pass through it. This matters most in narrow combat zones, where line of effect becomes a critical question.

5. Dam Destruction: The elemental may be fixated on destroying a dam, slipping in and out of narrow holes to widen them. The players must try to stop it — without collapsing the dam themselves.

6. Aftermath Hazards: When slain, the elemental should collapse into a pool of water. This can flood a boat, create slippery floors, or muddy terrain — if you want the death to still carry impact.