What it does
Shell Armor grants complete immunity to critical hits. The opponent's move cannot roll a critical regardless of their critical-hit rate modifiers — moves with guaranteed crits like Storm Throw and Frost Breath also fail to proc against the holder. A critical hit multiplies damage by 1.5 (since Gen 6), so Shell Armor effectively removes a 1.5× damage ceiling the opponent could otherwise stumble into.
Who runs it
Torkoal (0%) has zero usage in Champions. The alternative ability White Smoke (blocking stat drops) or Drought on certain forms makes Torkoal's Shell Armor slot non-competitive for now.
Torterra (62%) has real usage. Its Grass/Ground typing and physical bulk — 95 HP, 105 Defense — gives it a legitimate role in doubles as a physical wall or weather-adjacent support. The 62% reflects overall adoption; Shell Armor being the selected ability isn't guaranteed, but the Pokémon itself has competitive relevance.
How to use it
Shell Armor is a consistency tool. Crits are low-probability events — around 4.2% per hit on standard moves — but a surprise crit at a critical moment (pun noted) can flip a game. Slow, bulky Pokémon are the most vulnerable to this: they rely on surviving multiple hits according to plan, and a stray crit invalidates the damage calculation you relied on.
With Shell Armor, your damage taken is predictable. That predictability is the entire point.
Against opponents running forced-crit moves, Shell Armor is an active counter: Storm Throw and Frost Breath deal their damage but lose the guaranteed 1.5× bonus entirely.
Tips & strategy
Shell Armor provides no offensive benefit and doesn't block anything other than crits. If your opponent isn't running high crit-rate moves or forced-crit moves, the ability spends entire games doing nothing visible.
Battle Armor is mechanically identical — same crit immunity, different ability name, just distributed across different Pokémon.
Torterra's 56 base Speed means it will absorb multiple hits before it can respond in many matchups — exactly the condition where crit immunity has the most value.