Tower

A tower is a formation created by lifting a character and then lifting that character with another one. This can be used to throw characters to farther distances than lifting a single character can do. Towers can in theory have an unlimited amount of characters in it, but in practice only eleven is possible: a lifted enemy plus the ten units a player can control.

Each successive game in the series adds additional actions a tower can take up to Disgaea 6: Defiance of Destiny.

Protection
Towers make it harder for enemies to eliminate specific allies. Enemies can usually only attack allies at the absolute bottom of the tower holding up the rest of the tower allies. As such, putting allies at the top of the tower will make them harder to destroy than if they were at the bottom of the tower. However, a Monster unit can only be at the top of the tower, as monster class units cannot lift.

Prior to Disgaea 5: Alliance of Vengeance, towers can be used to protect allies and reduce the amount of allies that can be killed at once. Prior to Disgaea 5, when an ally holding up a tower is defeated, attacks during the enemy's turn that would target that ally will be dropped. Disgaea 5 changed this so that enemy attacks will not be dropped and after the ally holding up the tower is defeated, further attacks targeting that position will damage the unit dropped to the bottom of the tower.

Tower Attacks
In Disgaea 2: Cursed Memories, Tower Attacks were introduced, allowing up to ten player units to attack and deal damage to a single target at once. If the target is defeated, all members in the tower gain experience, which introduces a significantly easier way to grind multiple characters at once.

In Disgaea: Hour of Darkness and its ports, towers cannot attack using the Attack command or using a Special Technique. Disgaea 2 introduces the ability to attack using the attack command while in a Tower.

Disgaea 4: A Promise Unforgotten introduces special techniques that can be only used while in a tower of at least four units.

Tower Move
In Disgaea 4: A Promise Unforgotten, Disgaea D2: A Brighter Darkness, and Disgaea 5: Alliance of Vengeance, a Special Technique can be acquired that allows towers to move titled "Tower Move," which requires three or more members in the tower to use. With only three tower members in the tower, a tower can only move one space at a time, and the amount of tiles that can be traversed at once increases with the amount of characters in the tower. Characters can only move on an axis aligned to the tower, so diagonal movement is not possible.

Using Tower Move causes the tower to be flipped so that the character on top will be on the bottom. This allows the tower to then attack, or move again, likely in a different axis.

Tower Throw
A tower can throw the single unit on top using the special technique Tower Throw. This is available starting in Disgaea 4.