Stone is an ability of Kirby's in the Kirby and Super Smash Bros. series. When executed, Kirby will turn into a stone and drop onto an enemy, thus damaging it. This would work the same way in the Super Smash Bros. series, though to perform it the player controlling Kirby would have to press down B.
In the original Super Smash Bros., Kirby would just turn into a stone, though in Super Smash Bros. Melee Kirby would be capable of turning into a stone, a Thwomp, a garbage block from Panel de Pon, a 100 ton weight, and a spiked ball.
In Super Smash Bros. for Nintendo 3DS / Wii U, they finally updated Thwomp to its modern rendition.
There are two alternate forms of the move, introduced in Super Smash Bros. for Nintendo 3DS / Wii U
- Grounding Stone - Takes longer to transform but traps opponents in the ground if it hits.
- Meteor Stone - Takes longer to transform out but, meteors opponents it hits.
Kirby's Stone has some uses but, the transformation lag is very punishable. It can be used to avoid damage while falling and is okay at damage and knockback. Kirby's invulnerability while in Stone form is a decent way to avoid damage but, again the transformation takes a while. It does massive shield damage as well.
The Meteor Stone can be used to effectively edgeguard.