Somersault Flip is a move used by Marshall Law and Forest Law, where they do a somersault flip kick. It is executed by pressing 3+4. By pressing 3 right after 3+4, the Laws will do another flip. It can also be executed by pressing u/f+4,3 and as of Tekken 6, it can only be performed that way.
There are many variations of this move, as it also serves as a combo finisher for certain combo attacks, by pressing 3 or 4, depending on the combo attack the player performs. In addition to that, the characters Lee Chaolan, Paul Phoenix and Anna Williams also have a variation of this kind of attack.
Lee has many combos ending with a somersault flip, depending on the attack, and he can also perform it individually, but has a different imput than Law. With Paul, stay crouched for a few seconds until Paul does an animation to get Ki Power, then press u+2+3+4 (u+3+4 from Tekken 6 onward). With Anna, it is executed by pressing u+4 (as of Tekken 6), but without the second somersault kick. Lee can execute three somersault types, the first is a fast flip, performed by pressing u+4 while crouched but if U+4 is held he will perform a complete flip flying above the opponent dealing more damage. The most powerful flip, requiring U+3+4, will deal more damage. With good timing, Lee can perform the short flip twice in a row or chain the other somersaults to maximize damage.