When this move is used, Ivysaur will send a barrage of seeds ascending from its bulb, trapping opponents in the rapid hits and dealing repeated damage to them. At the start of the move, there is a hitbox at Ivysaur's sides to launch opponents into the attack. In Brawl, Bullet Seed can deal 40%-50% damage to a trapped opponent. If the opponent is trapped optimally (without the initial hit), the move can deal over 70% damage. If the special button is held, it will last up to 5 seconds. In Ultimate, the move's maximum potential damage output is reduced to about 20% damage. The move also has a finishing hit at the end which launches the victim away, making it less punishable, but reducing follow-up potential. If the special button is held, it will last up to 2 seconds.
In the Pokémon series, Bullet Seed is a Physical (as of Generation IV) Grass-type attack that was introduced in Generation III. In battle, Bullet Seed is a weak attack, only having 10 base power for each hit in Generations III and IV, and 25 base power for each hit in Generation V onwards. However, Bullet Seed can hit two to five times for each time the move is used. It is often learned at low levels by Grass-type Pokémon. Ivysaur could learn this move through TM09 in Generations III and IV.