Mass for the Dead

Mass for the Dead is a smartphone game developed by Exys Inc., and based on Kugane Maruyama's Overlord novel series. The website to pre-register for the game opened on June 25, 2018. The opening theme for the game was released on August 30, 2018 in a video promoting pre-registration. The game is free to play with in-app purchases.

Overlord -MASS FOR THE DEAD- was made available for iOS and Android. On November 8, 2018, it was announced that the game release would be delayed to early 2019. On February 13, 2019, it was announced that the game app would be available on February 21, 2019.

On March 3, 2020, the original theme song was replaced with another one by Myth & Roid. On March 31, 2020, Crunchyroll announced that pre-registration would be available for an upcoming English release of Mass for the Dead through its website. The English version of the game was released on April 20, 2020 for IOS and Android. On January 31, 2021, it was announced that the global version of Mass for the Dead will be permanently ending services. On March 31, 2021, Mass for the Dead was removed from the app stores but the game is still available for download in Japan.

Turn-Based Command Battles
In the turn-based battles, players will need to choose what action they are going to do.

The main actions are: "Attack," "Charge" (Special Skill Progress bar/MP), and "Defend." In addition, players can choose between three skills using Magic Points (MP) they receive every turn.

Modes

 * Automatic Mode: A function in the game that allows the player to play in automatic mode.
 * Accelerate Mode: A function in the game that allows the player to play at a faster pace.
 * Multiplayer Mode: Up to four players can play at the same time. A small screen located on the left-hand corner will allow a user to check all the actions of other players done in battle and plan accordingly. This mode allows a user to express how he/she feels during a situation using emoticon icons.

Intimate System
A place where users can get 'closer' to other players. When you are closer to these players a new event will appear. New stories will be unlocked and information on characters will be revealed.

Story
Momonga after bidding his friend Herohero goodbye opted not to log out of the game. — and finds himself still in the Great Tomb of Nazarick even after the shutdown's countdown.

Elsewhere a homunculus NPC gains awareness and finds the library of Ashurbanipal to be in disarray. Sensing something to be wrong, the homunculus heads immediately to the 10th Floor. To the homunculus’ horror, he finds the last defense to the Throne Room, the Golems of Lemegeton to be destroyed. Entering the Throne Rooms it is discovered to be in ruins with a battle in progress.

Main Story Chapters

 * Chapter 1: World of Chaos
 * Chapter 2: Wise King of the Forest
 * Chapter 3: Fractured Forest
 * Chapter 4: Fortress City E-Rantel
 * Chapter 5: Platinum Adventurer
 * Chapter 6: Request of the Golden Princess
 * Chapter 7: Trilateral Talks
 * Chapter 8: The Lost Hero
 * Chapter 9: Evil Darkness
 * Chapter 10: Crumbling Overture
 * Chapter 11: Demon Emperor's Feast
 * Chapter 12: Leader of Mankind
 * Chapter 13: End of Date
 * Chapter 14: Mountain Range Lord
 * Chapter 15: Crackling World

Memory of Chaos
Players can play character-specific quests that unlock after a character raises their intimacy levels.

Unit Scenarios

 * Unit Scenario: Master Trainer Aura
 * Unit Scenario: Unreliable Messenger of Nature Mare
 * Unit Scenario: Semi-Devil Form Demiurge
 * Unit Scenario: Heavy Knight of Purity Albedo
 * Unit Scenario: Bloody Valkyrie Shalltear
 * Unit Scenario: Ruler of the Glacier Cocytus
 * Unit Scenario: Butler of Steel Sebas
 * Unit Scenario: Sorcerer King Momonga

Trivia

 * The game's plot was supervised by series creator Kugane Maruyama according to his Twitter post. And was assisted by Satoshi Ōshio according to his profile.
 * Those that pre-registered had a chance to win a life-sized replica that happens to be the Staff of Ainz Ooal Gown. Pre-registration rewards included up to 500 Chaos Stones. The Twitter campaign ran from June 25 until July 31, 2018.
 * Voice actors from the Overlord Anime returned to play their roles in the game. They also be offered autographed cards as giveaways for the game's pre-registrations Twitter campaign.
 * The game featured re-enactment events of specific scenarios within the Light Novels and even multiple crossover events with other anime including: Konosuba, Re:Zero, The Saga of Tanya The Evil, Date A Live, Berserk, Slayers, Cautious Hero: The Hero Is Overpowered but Overly Cautious, The Rising of the Shield Hero, Magical Girl Lyrical Nanoha, So I'm a Spider, So What?, etc.