Comparison

MythoBar vs SillyTavern

Both let you play stories with an LLM. The difference is where the world lives. SillyTavern is excellent at fast, freeform character chat — the model improvises everything, including the facts. MythoBar runs a real simulation underneath the story, so the model never has to remember the world by itself.

That one choice is why a MythoBar worldline can run for a thousand scenes without the drift, amnesia, and self-contradiction that creep into a long chat.

SillyTavernMythoBar
Core unitA character card — one persona the LLM plays.A GamePack — a whole world: its rules, its cast, and its content, packaged together.
Where the world livesIn the LLM. The model is asked to act as if a game state exists.In a real, deterministic simulation that holds the authoritative state. The model writes prose on top of it.
Who decides what happenedThe LLM — it narrates and, in effect, invents the facts as it goes.The simulation decides who is where, what happened, and how much time passed. The LLM decides only how it reads.
Consistency over a long sessionDrifts. The model forgets, contradicts itself, and the world quietly changes.Stays coherent. Because the simulation — not the model — is the source of truth, the facts a story refers to hold up as it grows.
PipelineA single LLM call per turn.Several specialized agents with distinct jobs — directing the scene, acting the cast, and narrating.
HistoryA scrollback of chat messages, including your raw input.A sequence of floors — canonical, novel-like scenes. Your raw input steers the world but never lands in the record itself.
MemorySummaries that get truncated as the chat grows.Layered memory managed against a token budget, drawing on the simulation as ground truth.
Reuse across storiesCopy and paste character cards and lorebooks between chats.Packs are standalone and shareable — a whole world you can load, fork, and export as a novel.

SillyTavern is an independent open-source project, not affiliated with MythoBar. This comparison reflects the two products’ different design goals.

The one difference everything follows from

In SillyTavern, the LLM pretends a game state exists. In MythoBar, the game state actually exists — a deterministic simulation runs the world forward, and the LLM is one agent on top of it that decides the prose, never the facts.

Anything a pure function can decide is decided by the engine, not guessed by the model. That is what keeps a long story from quietly falling apart, and what lets the same world be loaded, forked, and shared rather than copy-pasted.

Questions

Is MythoBar a SillyTavern alternative?
Yes, for players who want long, consistent stories. SillyTavern is excellent for fast, freeform character chat. MythoBar is built for worldlines that stay coherent over hundreds of scenes, because a real simulation — not the LLM — holds the world together.
Why do long AI roleplay chats drift, and how is MythoBar different?
In a normal AI roleplay the LLM has to remember everything, so over a long session it forgets and contradicts itself. MythoBar keeps the canonical state — stats, time, locations, relationships — in a separate simulation, so the facts the story refers to stay consistent and the LLM is free to focus on the prose.
Can I bring my own world and models to MythoBar?
Yes. You can bring your own model key or spend credits against any model in the catalog, and you can bring your own world as a pack or settle into an existing one. Every worldline forks and exports as a novel.

Real world. Mythic story.

See what a story feels like when the world actually holds together.