Hobby Japan has announced that the fantasy light novel series Backstabbed in a Backwater Dungeon: My Trusted Companions Tried to Kill Me, But Thanks to the Gift of an Unlimited Gacha I Got LVL 9999 Friends and Am Out For Revenge on My Former Party Members and the World is receiving an anime adaptation. More details about the anime were not revealed.
Hobby Japan posted a video confirming the announcement in commemoration of Hobby Japan Novels’ 10th anniversary.
The original light novel series is written by Shisui Meikyo and illustrated by tef, and was first published by Hobby Japan on May 19, 2021. Ten volumes have been released as of July 2024, with an 11th volume set for release on November 19, 2024. The series originally began as a novel series on Shosetsuka ni Naro on April 17, 2020.
A manga adaptation by Takafumi Omae was launched in Kodansha’s Magazine Pocket website on May 25, 2021. Fourteen tankobon volumes have been released as of November 2024. Seven Seas Entertainment releases the manga in English for North America.

J-Novel Club releases the Backstabbed in a Backwater Dungeon light novel series in English digitally, describing the synopsis as:
When Light is kicked out of the Concord of the Tribes, his former comrades instantly turn on him. Light escapes this diabolical act of betrayal by the skin of his teeth…only to find himself in the deepest part of the Abyss, the most dangerous dungeon in the realm! To avoid being eaten by carnivorous monsters, he uses the Unlimited Gacha, his sole magical skill. But where it previously only produced junk items, this time Mei—a gorgeous Level 9999 fighter in a maid outfit — springs forth!
Fast forward three years and Light has carved out his own kingdom in this backwater dungeon, summoning more beautiful Level 9999 warriors who swear absolute fealty to him. Now a powerful Level 9999 Overlord himself, Light plans to ascend to the surface and take revenge on his betrayers one by one!