Getting Started with Garry's Mod Addons

Workshop subscriptions, gamemodes, and the spawn menu — your first hour in GMod

Garry's Mod modding is unusual because "modding" the game and "playing" the game are functionally the same activity. You install addons through Steam Workshop, pick a gamemode, optionally join a server, and the experience is whatever the community has built into that gamemode. There's no script extender, no plugin loader, no separate mod manager — Workshop and Lua handle everything.

This guide walks the standard flow on the current x64 build.

Step 1 — Make sure you're on x64

Garry's Mod transitioned to x64 in 2024. Steam's default install is x64. If you have the legacy 32-bit build for compatibility reasons (some old addons require it), you may need to opt into a specific Steam beta branch — but for most users, x64 is correct.

Open the Garry's Mod Workshop. Subscribe to anything. Steam downloads it.

For your first session, consider:

A map pack (search "rp_downtown" for the most-used DarkRP map, or "ttt_minecraft" for a TTT classic).
A vehicle pack like "TDM Cars" if you want to drive in sandbox.
A gamemode, the most consequential choice. TTT (Trouble in Terrorist Town) is the canonical multiplayer experience.

Step 3 — Pick a gamemode

From Garry's Mod's main menu → New Game → Gamemode dropdown. Your installed gamemodes appear here.

Common gamemodes:

Sandbox — the default. Build anything, no rules.
Trouble in Terrorist Town (TTT) — social-deduction multiplayer. The most-played gamemode.
DarkRP — roleplaying server gamemode. Heavy.
Prop Hunt — hide-as-an-object hide-and-seek.
Murder — Among Us-style social deduction.

Step 4 — Single-player vs server

For single-player: pick a gamemode, pick a map, click Start. Your installed addons are available in-game.

For multiplayer: browse the server list (Find Multiplayer Game). Most communities run TTT, DarkRP, or a custom gamemode. The server's installed addons are downloaded automatically on first join (this can be slow on a large RP server).

Step 5 — Configure addons

Most addons have no configuration — they just exist. Some (especially weapon and tool addons) add entries to the in-game spawn menus.

Spawn menu access:

Q (held) opens the spawn menu in sandbox mode.
Tabs across the top sort props, NPCs, weapons, entities, vehicles, and gamemode-specific categories.
Addons add their content to the appropriate tabs.

Step 6 — Hosting your own server

For private play with friends:

In Garry's Mod, New Game → set gamemode → tick Server.
Set a friend-only password if you want.
Share the IP from console → status or use Steam's invite friends feature.

For dedicated servers: download SteamCMD, install the GMod dedicated server tools, configure addons via the server's server.cfg and Workshop collection ID. This is more involved; many guides exist on the GMod wiki.

Common gotchas

Addon appears in Workshop but not in-game. Steam download incomplete. Restart Steam, verify Garry's Mod files via Steam → Properties → Local Files → Verify.
"Couldn't load addon." Usually a 32-bit-only addon on x64. Check the addon's Workshop page for x64 compatibility.
Server connection downloads forever. Some servers auto-download dozens of GB of addons. Pre-subscribe to the server's Workshop collection to avoid the download wait.
TTT player models look broken. Most TTT servers use custom player models from Workshop. Subscribing to the server's collection fixes this.
Crashes when opening spawn menu. Often a broken addon. Disable addons one at a time via the in-game Workshop tab to identify the culprit.

If you want to author your own Garry's Mod content, the GMod wiki (formerly developer.gmod.com) has the canonical Lua reference. Most "mods" are 100-line Lua files that hook into existing systems — the entry curve is genuinely accessible.