Search for a SillyTavern D&D extension and what you will actually find is D&D Dice, the official extension that adds real polyhedral dice to the app. It is good at its one job. The confusion starts when people expect it to be a D&D system, because dice are the smallest part of running 5e.
This post is the map: what the extension covers, what no current extension covers, and how far the built-in tools stretch before a purpose-built game becomes the easier answer. Details are current as of August 31, 2026; the full walkthrough with scripts lives in our SillyTavern D&D setup guide.
The extension that exists: D&D Dice
D&D Dice ships in SillyTavern's official installable catalog. Install it from Extensions > Download Extensions & Assets (git must be available on the machine), then use it three ways:
- The wand menu, for a quick visible roll you interpret yourself.
- The
/rollcommand, for formulas like/roll 1d20+5, plus a{{roll::1d20}}macro and aquiet=truemode for STscript pipes. - The function tool, which lets a compatible Chat Completion model with function calling enabled request a genuine random roll instead of writing a plausible number into the prose.
That last mode matters more than it looks. A number a language model writes is a narrative choice; a number the dice tool returns is a committed random result. If the model never calls the tool, you are back to fiction about dice rather than dice.
The extension that does not exist
There is no extension in the official catalog that installs a complete 5e game: no canonical character sheet, no legal-action gate, no initiative and condition tracker, no engine comparing totals to a DC. A complete "5e extension" would have to own all of that, and it would also have to win an argument with the narrator every time prose and state disagree, which is precisely the hard part.
So the working SillyTavern D&D stack is assembled, not installed:
| Need | What covers it | What stays manual |
|---|---|---|
| Random dice | D&D Dice extension | Choosing the roll, modifier, and target number |
| Rules reference | World Info entries | Enforcement, and context-budget discipline |
| Character state | Chat-local STscript variables | Validation and keeping the narrator current |
| Repeatable updates | Quick Replies | Writing and maintaining each script |
| Combat | One canonical ledger you maintain | Everything about it |
Each of those pieces is covered step by step in the setup guide, and the state layer specifically in SillyTavern game state.
Deciding whether to build or play
The honest framing is that SillyTavern gives you a workshop, not a game. For a tinkerer, that is the appeal: your model, your prompts, your scripts, your files, optionally fully local. The guide to running your own AI dungeon master goes further down that road.
The cost is that you are the rules engine. Every mechanic you add, Sneak Attack timing, concentration checks, death saves, is another workflow you write and another thing the narrator can contradict.
TableForge takes the opposite trade. The game engine runs the game, and the AI DM narrates on top of it: dice, HP, spell slots, conditions, and combat resolve in code, the character sheet updates itself, and up to six people can join the same browser campaign. You give up model choice and prompt access; you skip the entire assembly above. How the rules engine works explains the architecture, and the free first session is the fastest way to feel the difference.
Build the table if building is the fun part. If you searched for an extension because you wanted to be playing already, that is the signal worth listening to.