What it does
Storm Drain does two things: the holder takes zero damage from Water-type moves, and each Water move absorbed raises the holder's Special Attack by one stage.
What that +1 actually means in numbers. Take Gastrodon with a base Sp. Atk of 92. At Lv50 with no Stat Points invested, that sits around 126. After one absorbed hit, it jumps to roughly 189 — the same net gain as landing a half-strength Nasty Plot. That 189 Sp. Atk firing Earth Power puts many common physical cores into KO-or-forced-switch territory. The opponent's Water move cost them nothing useful and handed you a meaningful attack boost. That asymmetry is the whole point.
In doubles, Storm Drain also redirects. Every single-target Water move, regardless of who the opponent aimed it at, is pulled toward the holder. That's zero-action protection for your partner — identical in principle to Follow Me, but passive and free. Against spread Water moves (Surf, Muddy Water): in doubles, spread moves deal ×0.75 power already. When they hit a Storm Drain holder, that holder's share is fully absorbed. The opponent fires Surf across both targets and effectively lands one hit at reduced power — a terrible exchange on their end.
In singles, Storm Drain is simply a better Water Absorb for offensive Pokémon. HP recovery is capped; a Sp. Atk boost that you can immediately weaponize is not.
Who runs it
Gastrodon (Water/Ground) — the canonical user. Strong bulk, Recover, and Ground typing that already blanks Electric. Against rain teams, Gastrodon in doubles means the opponent's core attack type and the rain-boosted Electric pairing both hit a wall that grows stronger every turn they try it. Earth Power is the primary tool for cashing in the absorbed boost.
Clodsire (Poison/Ground) — Storm Drain patches the Water weakness that would otherwise threaten its bulk. Recover plus Poison-type coverage makes it a durable doubles glue piece; one absorbed Water move and it pivots into an offensive threat without costing a support turn.
Maractus (Grass) — Grass already resists Water, so Storm Drain here converts what would be a mild hit into a free boost. Against Water-heavy teams, Maractus becomes nearly impossible to chip through Water alone. Energy Ball or Petal Blizzard cashes the Sp. Atk gain offensively.
Any doubles partner shielding an offensive Water core. If your team fires Origin Pulse or Hydro Pump, positioning a Storm Drain holder alongside prevents the opponent from redirecting that threat toward your own Water-type attacker and simultaneously absorbs their counter-Water coverage.
How to use it
In singles: Pivot in on a predicted Water move — especially against a Choice Specs or Choice Scarf user locked in. You take zero damage and gain +1 Sp. Atk, effectively turning their scouting lock into your setup. Stay in after absorbing: the boost vanishes on switch-out, so the correct play is to stay and fire immediately unless the match-up demands an escape.
In doubles, standard turn pattern:
- Turn 1: Lead Storm Drain holder alongside your primary damage dealer. Opponent targets with a single-target Water move → absorbed, holder at +1 Sp. Atk.
- Turn 2: Holder fires Earth Power at boosted power while the damage dealer pressures or the opponent is forced into a bad switch.
Against Drizzle rain teams (Pelipper archetypes), one Storm Drain slot cuts the opponent's Water-type effectiveness roughly in half: single-target moves are fully absorbed, spread moves become one effective target at ×0.75. Combine with Protect on the turn the opponent switches in a counter, then fire on the clean turn.
Earthquake positioning: If your own team uses Earthquake, it hits your Storm Drain holder in doubles. Check whether the holder is a Ground or Flying type or carries Levitate before running both in the same slot — the timing collision can cost you.
Tips & strategy
Common mistake: hoarding the boost instead of using it. New players absorb a Water move, then Protect for two turns worried about taking damage, then eventually switch out — and the +1 is gone with nothing to show for it. The boost resets on switch-out, full stop. The right play: cash it out the same turn or the turn immediately after. Take the risk of staying in, fire the boosted special move, make the opponent pay for their Water click. Passive play with a Sp. Atk boost in hand is free value thrown in the bin.
Named counter: Grass-type moves. Gastrodon and Clodsire both carry a 4× Grass weakness. Leaf Storm, Energy Ball, Giga Drain — all of them delete a Storm Drain holder before the ability can matter. Any opponent who correctly reads your lead switches immediately to their Grass coverage. Plan the matchup: know when to Protect, when to bring in your own Grass check, and when to pull the Storm Drain user before it eats a Grass OHKO.
Knock Off destroys sustain. Storm Drain holders typically rely on Leftovers or Sitrus Berry to stay healthy across long doubles sequences. Losing the item reduces the number of turns they can realistically anchor the field.
Storm Drain vs Water Absorb decision: Pure defensive pivots without special moves to cash — Water Absorb's ¼ HP recovery is more consistent. Any Pokémon with a usable special move or a doubles redirect role: Storm Drain wins every time. The redirect alone in doubles is worth more than a small HP restore.