Cloyster looks like a glass cannon the moment you check its typing. Water/Ice takes double damage from four different types, and its Sp. Def sits at a paper-thin 45 base. That chart is the part every quick search answers. What most of those results skip is the turn that actually decides the fight: the one where Cloyster uses Shell Smash, its Speed and Attack roughly double, and none of those four weaknesses matter anymore because it’s not the one taking the hit — you are.
The Short Answer: Cloyster’s Four Weaknesses
Cloyster (Water/Ice) takes 2x damage from Electric, Grass, Fighting, and Rock. It resists Water (0.5x) and double-resists Ice (0.25x) — Ice moves do the least damage of any attacking type against it. Every other type deals neutral damage. There is no 4x weakness anywhere on this typing, which surprises players used to seeing Ice/Flying or Ice/Rock combinations get wrecked by a single move.
Why Water/Ice Stacks Exactly These Four Types (and Not a Fifth)
A dual-type chart isn’t looked up as one unit — it’s the two single-type charts multiplied together, type by type. Water alone is weak to Electric and Grass (2x each) and resists Fire, Water, Ice, and Steel (0.5x each). Ice alone is weak to Fire, Fighting, Rock, and Steel (2x each) and only resists itself. Run every one of the 18 attacking types through both charts and multiply, and the overlaps cancel each other out in two places: Fire lands as 2x on Ice but 0.5x on Water, so the combined hit is 1x — neutral. Steel does the same thing (2x Ice, 0.5x Water = 1x). That’s why Cloyster isn’t weak to Fire or Steel despite Ice alone being vulnerable to both.[1][2][3]
Compare that to a Pokemon whose two typings share a weakness instead of canceling one out. Aggron’s Steel/Rock typing stacks Fighting and Ground into genuine 4x weaknesses because nothing in either chart cancels them — that’s the mechanical difference between a Pokemon with a scary weakness chart on paper and one that’s actually a 4x liability in practice. Cloyster’s four weaknesses are all single 2x hits, which is a real problem against a Fighting-type lead but not the kind of one-shot vulnerability that ends a match before it starts.
The Full Weakness and Resistance Chart
| Multiplier | Types |
|---|---|
| 2x (weak) | Electric, Grass, Fighting, Rock |
| 1x (neutral) | Normal, Fire, Poison, Ground, Flying, Psychic, Bug, Ghost, Dragon, Dark, Steel, Fairy |
| 0.5x (resist) | Water |
| 0.25x (double resist) | Ice |
Version/patch note: this chart reflects the current 18-type system used since Fairy was introduced — no type-chart changes affect this matchup in any recent update, so it applies whether you’re building a team for ranked doubles or just checking a single fight. For the complete 18-type interaction matrix beyond just Cloyster’s two types, see our Pokemon type chart guide — note that Pokemon GO uses a different multiplier scale (1.6x/0.625x instead of 2x/0.5x) than the mainline games covered here, though the underlying type relationships are identical.
Who Actually Punishes Each Weakness
Listing four types without context is the same thin advice you’ll find everywhere else. Each of Cloyster’s weaknesses gets punished by a different kind of team, and knowing which one you’re facing changes how you play around it:
- Electric — the safest switch-in of the four. Electric moves can’t be resisted or nulled by anything in Cloyster’s own kit, and Electric-types typically out-speed a non-boosted Cloyster (base 70 Speed), so this is the check that works before Shell Smash is even a threat.
- Grass — strong on paper, weak in practice. Most dedicated Grass-types are slower than a Shell Smash-boosted Cloyster and get hit by a resisted-but-still-heavy Icicle Spear before their own move lands.
- Fighting — the one that matters most, because several Fighting-types carry priority moves (more on this below). Priority ignores the Speed boost entirely.
- Rock — effective offensively, but most Rock-types are physically bulky rather than fast, so they’re taking a boosted hit back unless they move first or resist what Cloyster throws at them.
Notice the pattern: three of the four “weaknesses” only matter if the attacker moves before Shell Smash resolves or survives the return hit. That’s the piece a plain type chart can’t tell you.
The Shell Smash + Skill Link Threat: Why the Chart Isn’t the Real Danger
Shell Smash raises Attack, Sp. Atk, and Speed by two stages each in a single turn, while lowering Defense and Sp. Def by one stage each.[4] On a Pokemon with Cloyster’s base 180 Defense, giving up one stage there is a fair trade. On its base 45 Sp. Def, one stage down turns an already-fragile stat into one of the worst effective Sp. Def scores at that point in the fight — which is exactly why Cloyster needs to end the game the same turn it sets up, not survive a second one.
That’s where Skill Link comes in. Icicle Spear and Rock Blast are both 25 base power multi-hit moves that normally land 2-5 times (35/35/15/15% odds per hit count).[5][7] Skill Link removes the randomness entirely — both moves always hit five times unless they miss.[2] Icicle Spear at five hits works out to 125 effective base power before STAB, and Ice STAB pushes that to roughly 187.5 — delivered on a Pokemon that just added two Attack stages. Icicle Spear also carries 100% accuracy against Rock Blast’s 90%, which is why competitive sets lean on Icicle Spear as the primary STAB and treat Rock Blast purely as coverage for the Steel- and Ice-types that would otherwise wall the Ice-only attack.[5][7]
The practical result: a Shell Smash Cloyster isn’t threatening because of its typing. It’s threatening because it converts a mediocre Attack stat and a middling movepool into a five-hit STAB nuke in a single turn, and the same turn’s Defense/Sp. Def drop only matters if it doesn’t win immediately.
Checks and Counters to the Shell Smash Icicle Spear Set
Generic “counter Water/Ice” advice fails against this specific set, because most Water- and Ice-resistant Pokemon still take a boosted hit and go down. The Pokemon that actually check a Shell Smash Icicle Spear Cloyster fall into three real categories, confirmed against community-verified matchup data:[6]
- Priority Fighting moves — Mach Punch and Vacuum Wave users hit before Shell Smash’s Speed boost matters at all, since priority ignores stat stages entirely. Cloyster’s only priority option, Ice Shard, can’t 2HKO a Pokemon carrying either move, so it has no way to answer this back.[6]
- Bulky Water- and Steel-types — Suicune, Alomomola, and Blastoise resist both Icicle Spear and Rock Blast’s Water-side coverage moves and can tank a +2 hit while retaliating; Steel-types resist Ice outright and shrug off a boosted Icicle Spear the same way. Empoleon is the standout single answer here, resisting every move in the set.[6]
- Status before the setup turn — Thunder Wave or a burn applied before Shell Smash goes off cripples the sweep at the source: paralysis guts the Speed advantage the whole set depends on, and a burn halves the Attack stat that Icicle Spear needs to be threatening in the first place.
The common thread across all three: none of them are “resist its typing” answers. They work because they either move before the boost applies or survive at full power after it does — the same logic that made three of the four weakness-chart types conditional above.
As a quick decision tree for teambuilding: if you need a check that works even when Cloyster moves first, run a priority Fighting move. If you’d rather wall it outright and threaten a KO back, run a bulky Steel- or Water-type. If you can act before the Shell Smash turn at all, Thunder Wave or a burn shuts the set down before it starts — and any one of the three is enough on its own; you don’t need all three on the same team.
Should You Fear This Set? A Player-Type Verdict
| Player type | What actually matters here |
|---|---|
| New player | Don’t overthink the four-type chart — just avoid letting a low-HP Pokemon sit in front of a Cloyster that’s already set up. Switch on the Shell Smash turn, not after. |
| Casual/campaign player | A single priority-Fighting move (even a weaker one, since priority beats the Speed boost regardless of raw power) is the cheapest reliable answer to slot into a team. |
| Competitive player | Run at least one of: a paralysis/burn source that outpaces base Cloyster, a bulky Steel- or Water-type, or a priority user — and know that a resisted-typing answer alone isn’t enough if it can’t survive a +2 hit. |
| Completionist | Track both variants separately: the physical Icicle Spear/Rock Blast attacker covered here, and mixed sets that add Hydro Pump or Ice Beam for special coverage against the Steel-types that wall the physical side. |
FAQ
Does Cloyster have any 4x weaknesses?
No, and this is worth stating plainly because it’s a common assumption for Ice-types. A 4x weakness requires both of a Pokemon’s types to be independently weak to the same attacking type — Water and Ice never share a common weakness, so every hit Cloyster takes lands at a clean 2x at most. Compare that to Ampharos’s Mega Evolution, which genuinely does pick up stacked weaknesses when its typing changes — Cloyster’s chart looks similarly scary on a spec sheet but doesn’t behave the same way in practice.
Is the weakness chart actually why Cloyster struggles competitively?
Not really, and that’s the point of this article. Once Shell Smash is up, Cloyster’s own attacks don’t care what resists them as much as raw power output suggests — a five-hit 187.5 effective-power STAB move still does serious damage even against a resistant target. The chart matters far more for what’s attacking Cloyster than for what Cloyster is attacking.
What’s the single best answer if you can only prepare for one thing?
A priority Fighting move. It’s the only answer on this list that works regardless of whether Cloyster already set up, because priority ignores the Speed stat entirely — every other check either needs to outpace the post-Shell Smash Speed or tank a hit that a resisted typing alone doesn’t guarantee surviving.
Should you run this set yourself, or just prepare to face it?
That depends on how much you value a one-turn win condition versus consistency. The set lives or dies on that single Shell Smash turn going through unpunished — against a team with any of the three checks above already in place, it has no follow-up plan, since both Defense and Sp. Def dropped a stage to get there.
Sources
- Cloyster Pokedex: stats, moves, evolution & locations — Pokemon Database
- Cloyster (Pokemon) — Bulbapedia
- Water / Ice Weaknesses, Resistances & Counters — NationalDex
- Shell Smash (move) — Bulbapedia
- Icicle Spear (move) — Bulbapedia
- What are some good counters for Cloyster? — PokeBase, Pokemon Database
- Rock Blast (move) — Bulbapedia
I've been playing video games for over 20 years, spanning everything from early PC titles to modern open-world games. I started Switchblade Gaming to publish the kind of accurate, well-researched guides I always wanted to find — built on primary sources, tested in-game, and kept up to date after patches. I currently focus on Minecraft and Pokémon GO.