Mörk Borg (Swedish: Dark Castle), rendered MÖRK BORG, is an apocalyptic fantasy role-playing game published by Fria Ligan in 2020 that features dark themes inspired by heavy metal music, frequent character death and a doom metal playlist.

RPG historian Stu Horvath described the central theme of the game as "what player characters do in the last days —— speed them up, work to stop them, or just try to get rich and enjoy themselves before the lights go out.

As critic Sara Elsam noted, the game involves "valleys riddled with undead, gothic cathedrals and a cursed forest ... cannibal warlocks, poison peddlers from beyond the void and hungry gut worms.

[6] In 2018, Swedish writer Pelle Nilsson designed a dark RPG while waiting in queue for eight hours to have a load of apples juiced.

However, a Kickstarter campaign crowdsourced enough funds to print a full-sized 92-page hardcover rulebook, published by Fria Ligan in 2020 with cover and interior art by Nohr.

Elsam noted that using the occult powers was a double-edged sword, for "while they let you bend reality, they will also have terrible consequences when they inevitably fail.

Meehan commented on the darkness of the game, saying, "All of this ... makes for a pretty mean RPG that we wouldn’t recommend to new roleplayers or anyone who isn’t up for having a depressing time."