The King of Fighters XI/Movement

Roll

A+B (Light Punch + Light Kick) / 4+A+B (away + Light Punch + Light Kick): role

Has invulnerability shortly before the end, but can be thrown (or attacked during recovery).

Ukemi/Recovery Roll

A+B (Light Punch + Light Kick) / 4+A+B (away + Light Punch + Light Kick) on before hitting the ground

Recovery roll can be used if the opponent attack or throw has soft knockdown properties, but loses its complete invulnerability. In Japanese matchvids you often see a 2A after a combo that can be recovered to prevent the opponent from rolling forward.

Guard Cancel Roll

A+B (Light Punch + Light Kick) during a blocked enemy attack

Costs a super bar. Fully invulnerable, even against throws (except for Vanessa, she can be thrown, probably a bug).

Roll Cancel

A+B (Light Punch + Light Kick) during your own normal attack (no special moves)

Costs 1 shift stick The character cancels the attack with a roll forward. Useful only for advanced combos (brings only a few characters something).