What it does
Leaf Blade is a Grass physical move that raises the user's crit rate by one stage each time it's used. It's also a slicing move, which means Sharpness applies a 1.5x damage multiplier. Single-target, contact.
Those two properties stack independently: the crit rate climbs with each use, and Sharpness lifts the base damage from the first hit. First click with a Sharpness user is already a boosted hit. Build in the crit rate and subsequent hits keep getting more reliable.
Grass-type physical coverage targets Water, Ground, and Rock types — all routinely present in doubles. The type has genuine weaknesses (Fire, Ice, Poison, Flying, Bug), so the Leaf Blade user needs protective coverage from the partner to avoid getting exploited before it can land hits.
Who runs it
Leafeon at 65% is the canonical user. High physical Attack, Grass STAB, and good Speed for a Grass type. The Sharpness interaction on top of STAB makes its damage output meaningful against Water and Ground targets.
Decidueye at 74% is Grass/Ghost with Leaf Blade as primary Grass STAB. With Sharpness as an ability option, the slicing boost applies and Leaf Blade hits hard. Ghost STAB fills the coverage slot that Grass can't, so the two STABs complement each other cleanly.
Gallade at 26% uses it as Grass coverage rather than STAB. Psychic/Fighting needs Water and Ground coverage, and Leaf Blade fills that. The slicing boost from Sharpness would apply if Gallade ran it, but it usually doesn't — the raw coverage value is what earns the slot.
How to use it
In doubles, aim Leaf Blade at Water or Ground types that threaten your team. Getting them off the field early removes the pressure they're putting on your other Pokémon.
Decidueye's two physical STABs — Ghost and Grass — cover distinct targets. Ghost for Psychic types, Grass for Water and Ground. You're reading the field and picking which STAB matches the target; both are live options every turn.
Crit stacking same idea as Night Slash: click it for the damage, not to wait for a stacked crit. Every use makes the next one more dangerous.
Tips & strategy
Sharpness is the best pairing for Leaf Blade — it's the reason the slicing classification matters. Decidueye with Sharpness jumps up a meaningful damage tier compared to running a different ability.
Scope Lens also works with the crit stacking — two uses puts you at a high crit rate. Whether that beats another item comes down to what else your team needs from that slot.
Grass coverage doesn't hit everything. Fire, Flying, Poison, and Ice types all resist or counter Grass STAB. The partner needs to cover those threats, or the Leaf Blade user gets exploited before landing meaningful hits.