Dice Maiden — Rust Edition

A Discord dice rolling bot for tabletop RPGs. Supports complex dice expressions, exploding dice, keep/drop, success counting, and built-in aliases for 30+ game systems.

A complete rewrite of the original DiceMaiden Ruby bot in Rust.

Add to Your Server

Click here to add Dice Maiden

The bot appears in your default public channel with permission to read, send, and manage messages.

Users need the "Use Application Commands" permission to use slash commands.

To restrict the bot to specific channels, go to Server Settings → Integrations → Dice Maiden.

Commands

Command	Description
/roll <dice>	Roll dice using RPG notation
/r <dice>	Short alias for /roll
/help [topic]	Help — topics: basic, alias, system, a5e, aliens, mothership
/purge <count>	Delete recent messages (requires Manage Messages)
/roll donate	Support information
/roll bot-info	Bot statistics

Rolling Dice

/roll 2d6 + 3           # Basic roll with modifier
/roll 4d6 k3            # Keep the 3 highest
/roll 10d6 e6 k8 +4     # Explode 6s, keep 8 highest, add 4
/roll 4d10 t8 ie10 f1   # Success counting with botches
/roll 6 4d6             # Six sets of 4d6
/roll (Fireball) 8d6 ! AOE   # Labeled roll with a comment

Full syntax reference and game system aliases →

Self-Hosting

Requires Rust 1.90+ and a Discord bot token. SQLite is created automatically.

git clone https://github.com/Humblemonk/dicemaiden-rs.git
cd dicemaiden-rs
cp env.example .env      # add your DISCORD_TOKEN
cargo build --release
cargo run --release

Create your bot at the Discord Developer Portal and invite it with Send Messages, Use Slash Commands, Manage Messages, and Read Message History.

Environment Variables

See env.example for the full annotated list.

Variable	Required	Description
DISCORD_TOKEN	✓	Bot token from the Discord developer portal
DATABASE_URL		SQLite path — defaults to ./main.db, created if missing
GUILD_ID		Register commands to one guild for instant testing
SHARD_COUNT		Shards for this process — defaults to 1
USE_AUTOSHARDING		true lets Discord pick the shard count
SHARD_START		First shard ID (multi-process sharding)
TOTAL_SHARDS		Total shards across all processes (multi-process sharding)
MAX_CONCURRENCY		Hint only — Discord overrides with your bot's real limit
RUST_LOG		Log level — defaults to info

Container

A production Dockerfile is included — build it directly rather than copying one out of these docs:

docker build -t dicemaiden-rs .
docker run --env-file .env -v dicemaiden-data:/app/data dicemaiden-rs

Systemd service

[Unit]
Description=Dice Maiden
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=dicebot
Group=dicebot
WorkingDirectory=/opt/dicemaiden-rs
Environment=RUST_LOG=info
EnvironmentFile=/opt/dicemaiden-rs/.env
ExecStart=/opt/dicemaiden-rs/target/release/dicemaiden-rs
Restart=always
RestartSec=10
TimeoutStartSec=300
TimeoutStopSec=120

# Security hardening
NoNewPrivileges=true
ProtectSystem=strict
ProtectHome=true
ReadWritePaths=/opt/dicemaiden-rs/data
PrivateTmp=true

[Install]
WantedBy=multi-user.target

Multi-process sharding

Each process owns a contiguous shard range and shares one SQLite database.

# 3 processes handling 64 shards total
SHARD_COUNT=21 SHARD_START=0  TOTAL_SHARDS=64 ./dicemaiden-rs &   # shards 0-20
SHARD_COUNT=21 SHARD_START=21 TOTAL_SHARDS=64 ./dicemaiden-rs &   # shards 21-41
SHARD_COUNT=22 SHARD_START=42 TOTAL_SHARDS=64 ./dicemaiden-rs &   # shards 42-63

Contributing

Setup, code standards, testing patterns, and the process for adding a new game system are in CONTRIBUTING.md.

License

GPLv3

Support

• Open an issue for bugs or feature requests
• Join the Discord for help and discussion
• roll_syntax.md for dice syntax questions