
A technique called Veil Off can be utilized if a character has more than half a bar of meter, giving a "burst" shockwave, sending the opponent and a powered up state for damage boost and temporary use of infinite super meter. When their health is below 30%, characters can use Infinite Worth EXS, an extremely strong super activated by pressing four buttons. Characters spend half a meter for powered-up versions of special moves, or a full bar for Infinite Worth move, a high-damage super attack. A traditional super meter known as the EXS Gauge fills up whenever players can attack or get hit. However, incorrectly guarding moves with Shield causes a state known as GRD Break, which locks a character out of any techniques with GRD. Whichever character has more GRD at the end of a cycle gains a temporary "Vorpal" buff, improving their moves and damage, and using Chain Shift, which cancels any move, resets the character to a neutral state and receives extra meter for the GRD. GRD is a tug-of-war mechanic to reward players for defense or offense, for them to use Shield, an enhanced defensive technique Assault, an air dashing move and Force Functions, a character-specific action serving as offense or a temporary buff. Attacks can cancel each other in any order, and into special and super moves. It uses three attack buttons and a fourth one tied to the "GRD" meter. The game has similar mechanics to Melty Blood, Guilty Gear and BlazBlue. It received many updates for adjustments and characters.

Under Night In-Birth is a 2D fighting game co-developed by Ecole Software and French-Bread.
