Last Word is an open world, PvP centered MMORPG. In this game, the player will control two characters almost simultaneously while in battle. The main character will be on the physical plane while the other character is the main character's soul, and will be on the spiritual plane. A character on a different plane cannot damage each other unless under certain conditions. In Last Word, the player is only considered defeat if the physical character is knocked out. However, knocking out or rendering the spirit character unable to fight will greatly reduce the physical character's combat capability.

The player will have limited control over their spirit character for the majority of the time. In order for the character to take full control over their spirit character and utilize their powers, the player must use their "Last Word". The "Last Word" is the "last resolve" or "final skill sets" since the skill summons the spirit character to the physical plane, and provides extreme character enhancement or effects.

The "Last Word" is a player specific special ability. The player may only choose one Last Word for the rest of their journeys and cannot be changed. Some "Last Word" allows the player to teleport and swap locations with their spirit. Some can take the player's physical character into the spirit plane. Conditions and requirements for activating a "Last Word" depend on how much the said "Last Word" would affect the battle outcome. For example "Last Word" that stops time or dramatically change the game environment can only be used every few weeks.