The Log Horizon light novel series was first released in web format by Mamare Touno. As of April 16, 2017 thirteen complete volumes have subsequently released online, and eleven volumes have been published by Enterbrain. Hara Kazuhiro illustrates the published novels.
Yen Press has licensed the series for its light novel publishing section, Yen On. The first volume was released in April 2015, with a volume being published every three months.
- The Catastrophe arc
- Covered in volume 1.
Elder Tale is a long-lived, highly popular MMORPG that has millions of players. On the Japanese release of the twelfth expansion pack, an extraordinary event occurs that finds the players logged into the game at that time inside a world that looks just like the game's. Despite having many superhuman abilities such as revival after death and massive stamina, this world has its deterrents, such as flavorless food and the inability to return to the real world. Shiroe and his two friends adjust to living in this new world with the Crescent Moon Alliance, a guild whose members are friends with Shiroe.
- Saving Serara arc
- Covered in volumes 1 and 2.
The Crescent Moon Alliance reveals that one of its young members is trapped in another player city and their strongest members must embark on a mission to save her. Realizing their slim chances of getting to and from Susukino in a reasonable time frame, Shiroe's Party decides to go in the guild's stead. After reaching Susukino, Shiroe realizes that Serara's benefactor is his old friend Nyanta. With Nyanta and Serara's help, the group fights their way out of Susukino and head back to Akiba. Along the way, Nyanta reveals that he has discovered a way to create flavorful food, and Shiroe realizes that the People of the Land, commonly regarded as NPCs devoid of personality and life, now are just as real as they are.
- Round Table Alliance arc
- Covered in volume 2.
Upon returning to Akiba, Shiroe is alarmed by Marielle's explanation of the changes in Akiba since he had left. The major guilds rule the city and take all the best resources for themselves, leaving smaller guilds and solo players in the dust. Even worse, a malevolent guild called Hamelin has tricked and enslaved younger players in order to make a profit off of their EXP Pots. Realizing that two kids he had been mentoring prior to the Catastrophe, Minori and Touya, had been taken in by this guild, Shiroe decides to step up and do something about it after some encouragement from Nyanta. With the rest of his party, sans Serara, he forms Log Horizon and, with the Crescent Moon Alliance, begins to take action. He revitalizes the economy with Nyanta's newfound cooking method and, with that, acquires the power and leverage to call a meeting with Akiba's strongest guilds. The guilds, with the exception of one, agree with Shiroe's call for a form of this government in this lawless world, and form the Round Table Alliance.
- Summer Training arc
- Covered in volume 3.
- Return of the Goblin King arc
- Covered in volumes 3 and 4.
- Libra Festival arc
- Covered in volume 5.
- Fallen Guardian arc
- Covered in volume 6 and runs concurrently with the Gold of the Kunie arc.
- Gold of the Kunie arc
- Covered in volume 7 and runs concurrently with the Fallen Guardian arc.
- Route 43 arc
- Covered in volume 8.
- Go East! arc
- Covered in volumes 9, 11, and 15. Volume 9 runs concurrently with volume 5 and volume 11 takes place a bit before volume 10.
- Homesteading the Noosphere arc
- Covered in volume 10.
- Collapse of the Round Table arc
- Covered in volume 12.
- Nightingale's Song
- Covered in volume 13.
- Twilight Orphan
- Covered in volume 14.
List of Light Novel Volumes
| Log Horizon 1: The Beginning of Another World|
| March 31, 2011 (JP)|
April 21, 2015 (EN)
| ISBN 978-4047271456 (JP)|
ISBN 978-0-316-38305-9 (EN)
| Log Horizon 2: The Knights of Camelot |
| May 30, 2011 (JP)|
July 21, 2015 (EN)
| ISBN 978-4047272989 (JP)|
ISBN 978-0-316-26381-8 (EN)
| Log Horizon 3: Game's End, Part 1|
| August 31, 2011 (JP)|
November 17, 2015 (EN)
| ISBN 978-4047274136 (JP)|
ISBN 978-0316263849 (EN)
| Log Horizon 4: Game's End, Part 2|
| September 30, 2011 (JP)|
March 22, 2016 (EN)
| ISBN 978-4047275430 (JP)|
ISBN 978-0316263856 (EN)
| Log Horizon 5: A Sunday in Akiba|
| November 30, 2011 (JP)|
July 19, 2016 (EN)
| ISBN 978-4047276697 (JP)|
ISBN 978-0316263863 (EN)
| Log Horizon 6: Lost Child of the Dawn |
| March 30, 2013 (JP)|
November 15, 2016 (EN)
| ISBN 978-4047282353 (JP)|
ISBN 978-0316263870 (EN)
| Log Horizon 7: The Gold of the Kunie |
| December 20, 2013 (JP)|
January 2, 2014 (JP special ed.)
March 21, 2017 (EN)
| ISBN 978-4047291751 (JP)|
ISBN 978-4047291768 (JP special ed.)
ISBN 9780316263887 (EN)
| Log Horizon 8: The Larks Take Flight|
| September 29, 2014 (JP, special ed.)|
June 20, 2017 (EN)
| ISBN 978-4047299269 (JP)|
ISBN 978-4047299276 (JP special ed.)
ISBN 978-0316470957 (EN)
| Log Horizon 9: Go East, Kanami!|
| March 27, 2015 (JP)|
October 31, 2017 (EN)
| ISBN 978-4047301900 (JP)|
ISBN 978-0316470971 (EN)
| Log Horizon 10: Homesteading the Noosphere|
| September 30, 2015 (JP)|
February 20, 2018 (EN)
December 11, 2018 (EN digital)
| ISBN 978-4047306745 (JP)|
ISBN 978-0316471053 (EN)
| Log Horizon 11: Krusty, Tycoon Lord|
| March 20, 2018 (JP)|
January 29, 2019 (EN)
| ISBN 978-4047272309 (JP)|
ISBN 978-1975329419 (EN)
| Log Horizon 12: Collapse of the Round Table|
|ISBN 978-4047352483 (JP)|
The following volumes have been released online, but have not been formally published:
- Volume 13: Nightingale's Song (夜啼鳥の唄; completed April 16, 2017)
- Volume 14: Twilight Orphan (黄昏の孤児; updated March 25, 2018)
- Volume 15: Coppelia, Tiered Islands (コッペリア；ティアード・アイランド; announced at the Re:Fraction event)
- Volume 16: Theldesia's Friday (セルデシアの金曜日; announced at the Re:Fraction event)
List of Side-Story Volumes
| Log Horizon Side-Story: Kushiyatama, Do Your Best!|
(ログ・ホライズン 外伝 櫛八玉、がんばる!?)
|September 30, 2015||ISBN 978-4047306592|
| Log Horizon Side-Story: New Land of Adventure|
(ログ・ホライズン 外伝 新たなる冒険の大地?)
There are several different official translations for the light novels.
- English - Publisher: Yen On; Translator: Taylor Engel
- Chinese (Simplified) - Publisher: Guangzhou Tianwen Kadokawa
- Chinese (Traditional) - Publisher: Kadokawa Taiwan; Translator: Haniwa
- French - Publisher: Ofelbe; Translator: Marie-Saskia Raynal
- Korea - Publisher: Daewon C.I.; Translator: Min Yu Seon (민유선)
- Portuguese - Publisher: NewPOP Editora; Translator: Karen Kazumi Hayashida
- Poland - Publisher: Studio JG; Translator: Paulina Tuczapska
- Thai - Publisher: SE-ED; Translator: เซเบอร์ (volumes 1-4), ไคโตะ ฮากิวาระ (5+6)
- tounomamare.com: Mamare's official site (Japanese)
- Web novel: A site where Mamare publishes the initial version of the Log Horizon chapters. (Currently on volume 14.) (Japanese)
- Yen On's official page (English)
- BookWalker (English, digital edition)
- skythewood: Completed up to volume 7; further translations have ceased with Yen On's license.