Three Frame Bomb Jump
A Three Frame Bomb Jump (3FBJ or FBJ) is a type of Bomb Jump. It gains more height than being hit by a single bomb, but less height compared to every other bomb jump, including Double Bomb Jumps. It takes advantage of Samus's vertical speed when being hit by a bomb. When Samus is rising after being hit by a bomb, the hitbox of a bomb is large enough that one could hit the Morph Ball while it's rising without having to lay 3 bombs or more. FBJs are a required component of performing RGBJs.
To perform an FBJ, lay two bombs within 3 frames of each other.
Notable Uses
FBJs make single bomb jumps and BSJs significantly easier by keeping the time it takes to perform the bomb jump identical but greatly increases height.
FBJs single bomb jump use cases can be seen in the Furnace bomb jump to skip Spider Ball.
One of Arboretum's high level room Strategies involves performing a BSJ up to a branch, which can be precise using a single bomb, but an FBJ's increased height improves the leniency of the trick.