Overlord

Overlord (オーバーロード, Ōbārōdo) is a Japanese light novel series written by Kugane Maruyama and illustrated by so-bin. It began serialization online in 2010, before being acquired by Enterbrain. Thirteen volumes have been published since July 30, 2012. A manga adaptation by Satoshi Ōshio, with art by Hugin Miyama, began serialization in Kadokawa Shoten's manga magazine Comp Ace from November 26, 2014. Both the light novels and the manga are licensed in North America by Yen Press, with a release date of November 8, 2016.

The anime television series adaptation by Madhouse consists of 3 seasons with 13 episodes each, with the first season airing from July 7 to September 29, 2015. Two compilation anime films recapping the events from the first season were released in Japan on February 25, 2017, and March 11, 2017, respectively. The second season ran from January 9 to April 3, 2018, with the third season premiering later the same year on July 10, 2018, after which the last episode aired on October 2, 2018.

Plot
In the year 2126, a Dive Massively Multiplayer Online Role Playing Game or DMMORPG called Yggdrasil was released. It stands out among all other DMMORPGs due to its unusually high ability for the player to interact with the game. After an intense 12-year run the game servers are about to be shut down. Within the game exists a guild, Ainz Ooal Gown, once consisting of 41 members and credited as one of the strongest guilds in the game. Now only 4 of the members remain, the other 37 having quit the game. Of those 4 only one, an elder lich character named Momonga, continues to play as the guild leader and maintaining their headquarters, The Great Tomb of Nazarick. He invites the remaining guild members but of those only one appears and only for a short while before leaving. While saddened by this, he accepts the reality that his friends have their other lives (both lives are real) to take care of and decides to stay logged in until the servers shut down.

When the shut-down time arrives however, Momonga finds that the game hasn't vanished. Instead it appears as if Yggdrasil has been recreated as its own reality along with its various NPCs having been brought to life while Momonga has been trapped in the form of his game avatar, leaving him unable to use the normal player functions, such as General Message, or even to log out. With no other option, Momonga sets out to learn if anyone from the real world is also in this new world with him. Taking on the name of Ainz Ooal Gown, a message to any other players, Momonga begins exploring the world in an attempt to figure out what has happened while searching for anyone or anything that could help him solve this mystery, while ensuring the safety of Nazarick.

Light Novels
The light novel series written by Maruyama, with illustrations by so-bin, began its serialization online in 2010 via the novel publishing website Arcadia. It was also uploaded to the novel publishing website Shōsetsuka ni Narō in 2012, prior to Enterbrain's acquisition. As of September 30, 2017, the series has been published by Enterbrain in twelve volumes, with the first volume releasing on July 30, 2012, and the twelfth volume releasing on September 30, 2017. Yen Press announced its license to the series in October 2015 for North America and began publishing the novels in English, with the first volume releasing on May 24, 2016.

Web Novel

 * An online novel, that the Overlord series is based on until the eighth volume deviates from its Light Novel counterpart.

Drama CD

 * Special side stories of events that took place in the Overlord series, and were mentioned and spoken of in the Light Novel.

Manga

 * It is drawn and written based on the Overlord series' Light Novel plot. A manga adaptation with art illustrated by Hugin Miyama began serialization in Kadokawa Shoten's seinen manga magazine.

Anime

 * Based on the Light Novels, the Overlord series had its own anime television adaptation done by Madhouse for three seasons.

Specials

 * Bundled with the Overlord series, it has inspired an anime special based on the Pleiades, aptly titled, Pure Pure Pleiades, featuring super chibi characters.

Music

 * So far, two songs have been composed for the first season of the anime in the Overlord series: Clattanoia and L.L.L.. The second season songs include Go Cry Go, by OxT, and Hydra, by Myth and Roid. The third season songs include Voracity, by Myth and Roid, and Silent Solitude, by OxT.

Trivia

 * According to Maruyama, one of the reasons why he started writing the Overlord series is because his TRPG group of buddies stopped gathering and that they were too busy to play "Dungeon and Dragons" with him. Even within the settings of Overlord, TRPG plays a big part in it.
 * Also, Maruyama stated that the world of Overlord series operates on the law of the jungle, so he write as if the strong are good and the weak are bad. While some may view their actions as evil, they act on their perception of good.