Knockback is mechanic used in Riviera: The Promised Land and Gungnir. Originally, skills with knockback were used mostly by demons and forced the party's Formation to reverse.

In Gungnir, skills with the added knockback effect will force the target one tile away from where the attack landed in the direction the user is facing. If an adjacent unit is occupying the space, both the target and the unit(s) in line will be forced to move, with those who were not targeted taking only minor damage. If used against a wall or obstacle, the target will take a small amount of obstacle damage in addition to the attack, but will remain in their original tile position. If a unit is forced out of the border of the map by knockback, it is considered a Zone Out and that unit will be permanently expelled from the battle, behaving identically to a flee. Knocking a unit into an abyss on the map has a similar effect, but instead counts as a death; no corpse is left behind to loot due to the missing floor tiles.

Players should take care not to let their own units be knocked out of the battlefield, especially the Ace; if the Ace is knocked out, the battle immediately ends in failure. It should also be noted that boss units such as Bacchus are completely immune to knockback, preventing players from cheesing a boss out with little effort.