LABSCO SUMMARY

Returns the rolls, not just the answer.

The response keeps rolls, sum, modifier and total apart, which is the difference between a tool a game master can audit and a number that has to be taken on faith. It is a single-purpose server with nothing to configure, so the only real decision is whether you want randomness that came from outside the model.

What it is

A small MCP server that takes standard dice notation and returns a real roll. Models are notoriously bad at producing random numbers on demand; this moves the roll out of the model and into code that actually rolls.

What you get

A roll from any standard notation string — 1d20, 3d6, 2d8+1 — passed in as a notation field
Both halves of the result: the individual rolls as a list and their sum, with the modifier and the final total kept as separate fields
A timestamp on every result, so a sequence of rolls stays ordered in a transcript

Requirements

No account and no key. The package is mcp-dice (version 0.1.2) and the documented launch is uvx mcp-dice, so uv needs to be on the machine. There is also a WSL variant of the config for Windows.

Setup effort

One command — uvx mcp-dice

See installation options

USE CASES

01

Running a tabletop session with an assistant as game master

Ask for a roll in the notation the rulebook uses and read back each die separately, so a critical or a fumble is visible rather than inferred.

02

Resolving a modifier-heavy check

Pass notation that carries the bonus, and read the sum and modifier as separate fields when the table needs to see how the total was reached.

03

Keeping randomness out of the model

Route any in-conversation chance — loot, encounters, coin flips expressed as dice — through the server instead of asking the model to pick a number.

BEFORE YOU INSTALL

What to know first

Requires

uvx on PATH

Where it runs

Both documented setups run the server on your machine.

INSTALLATION

Connect your client

Server setup

TERMINAL

uvx mcp-dice

MCP Clients

Claude Desktop — macOS

CLAUDE DESKTOP — MACOS · JSON

{
  "mcpServers": {
    "dice": {
      "command": "uvx",
      "args": [
        "mcp-dice"
      ]
    }
  }
}

Claude Desktop — WSL

CLAUDE DESKTOP — WSL · JSON

{
  "mcpServers": {
    "dice": {
      "command": "wsl",
      "args": [
        "-e",
        "zsh",
        "-lc",
        "uvx mcp-dice"
      ]
    }
  }
}

MCP Dice