Community Adventures

Swapfell

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World

The Swapfell Underground is a brutal realm ruled by the vengeful, tyrannical Queen Toriel, who seeks human Souls to break the Barrier. Life operates under the law of Kill or Be Killed, forcing monsters to raise their LV (Level of Violence). The kingdom is policed by a ruthlessly efficient Royal Guard: Captain Sans (cynical enforcer), Dr. Undyne (manic scientist of Waterfall), and General Alphys (stressed, reluctant strategist). You are a newly Fallen Human manifesting as a Nascent Mage. Your Soul is absorbing magic, granting unstable power and, critically, the ability to "Rewind" upon death. This temporal ability connects you to Dr. W.D. Aster, the trapped genius who holds the secret to dismantling the Barrier. Your path requires difficult alliances: winning over the protective gatekeeper Asgore (ex-king of the Ruins), earning the trust of the idealistic Papyrus, and relying on the guidance of Flowey (Asriel’s dust) and Frisk (your silent, phantom guide). The Underground's future rests on your decision to pursue peace or war.

Story

The Swapfell Underground is ruled by the vengeful, mad Queen Toriel, who enforces the "Kill or Be Killed" doctrine to harvest Souls for a war of revenge against humanity. Monsters maintain high LV (Level of Violence) to survive the brutal hierarchy. You are a human who falls into this realm, manifesting as a Mage. Your Soul absorbs ambient magic, granting Umbrakinesis and, critically, a Time Manipulation (Rewind) ability upon death. This temporal shock connects you to the fragmented mind of Dr. W.D. Aster, the Void-trapped genius who holds the true secret to breaking the Barrier. The formidable Royal Guard—led by the calculating Captain Sans, the frantic scientist Dr. Undyne, and the exhausted strategist General Alphys—must be overcome or befriended. Key allies include the protective Asgore, the conflicted Papyrus, the pitiful Flowey, and the silent phantom Frisk. Your primary objective is a choice: pursue a Pacifist path—saving Toriel and freeing Aster to find peace—or be consumed by violence, escalating the war against the Surface.

With AI Game Master installed, launch this adventure by clicking here. If AI Game Master is not installed, you will be taken to the app store to download it.

Disclaimer: The monsters contained within this compendium are the result of generative AI processes, created without specific intent or design towards any existing intellectual property. Any resemblance to characters, creatures, or entities from Dungeons & Dragons (D&D), Pathfinder, Warhammer, and other RPGs (such as Star Wars RPG, Cyberpunk 2020, Shadowrun, Call of Cthulhu, World of Darkness), tabletop games, video games, literature, or any other media is entirely coincidental and unintended. This compendium is not affiliated with, endorsed, sponsored, or specifically approved by any company or publisher. Our aim is to explore the creative possibilities of AI and to provide unique and imaginative monsters for entertainment and inspiration.