Disgaea is a turn-based strategy series, not unlike Fire Emblem, where various units fight on a board divided into squares (a grid). In any particular mission there are two teams, that of the player and the computer. The player has the oppurtunity to move all of their units and have their unit undertake an action (use item, attack etc) before their turn ends and the computers turn begins, the two teams take turns in this way with the ultimate goal usually being to defeat all units in the other team.
Each mission begins from a central hub, where the player can recruit new characters to the party based on experience each character has earned in battle, current characters can be healed at the hub and new items can be bought with money earnt in battles.
There is also an Item World gateway; here, the player can select any item in the party's inventory and enter it. The levels for an item are randomly generated but depend on a number of factors based on the item itself such as its rarity or power. By descending through the Item World, the player can improve the abilities of the item as well as free Guardians that live in the item. These Guardians impart certain benefits to the item, such as increased in attack or defense values, and once they are freed, they can be moved between items freely.
Each Mission in the Disgaea series follows a basic pattern.
Initially the player selects which characters they will use (from a portal) and moves them around the map, the player can plan actions with these characters (once an action has taken place the character cannot move) and when they use the "Execute" function all planned actions will take place (in the order they were planned). If the player has not used all of there characters, that is to say some may still perform actions, their turn continues, if they have no characters left with actions remaining there turn ends (turns can also be ended manually).
Once the players turn has ended the computer takes a turn (the computers units begin on the map, they do not exit from a portal initially like the players). There is a chance that the players (or computers) characters will counter attack when attacked, adding a level of strategy to who should be attacked, likewise when a character attacks whilst standing next to another ahracter on there team there is a chance for a combo where 2 (or more) characters will attack at once whislt only using one characters action.
These turns continue until one team is defeated (or a different objective is met).
Across some boards are glowing colored spaces and special objects called "Geo Symbols". When these are placed on a colored field, they impart a bonus or penalty to all battle participants on the same colored field; such bonuses can also stack if multiple Geo Symbols are on the same field. A character can destroy a Geo Symbol which will cause all the field spaces it affects to cause some damage to the characters on them as they turnto another color determined by the destroyed Geo Symbol. It is possible to arrange a chain of these effects, each chain increasing the amount of damaged earned and increasing the bonus score for the mission. As with characters, Geo Symbols can also be lifted and thrown as to affect the board's bonuses.
Character towers can also be made with the lift ability, reflecting Disgaea's quirky attitude.