Run your gamemode in the game world

Set Surface = GamemodeSurface.World. Side Hustle then boots a scratch world before it calls your launch callback.

You need: a registered gamemode. See Add a gamemode.

The scratch world is a fresh copy of the default save on every launch. Side Hustle never touches a real save slot.

Steps

Set the surface:
```
Surface = GamemodeSurface.World,
```

Turn on the world rules you need with a preset. Each preset only switches flags on.

WorldHygiene.CleanWorld(descriptor, "My Guide Quest");   // quests blocked except the named ones, no intro, no saving
WorldHygiene.Arena(descriptor);                         // CleanWorld, plus no NPC reaction to gunfire and no player death

Or set the flags yourself:

Flag	Effect for the session
`BlockVanillaQuests`	No vanilla quest starts. `AllowedQuestTitles` lists the exceptions. Matters on the host.
`SkipIntro`	No intro cutscene and no character creator.
`BlockSaveDuringSession`	Every vanilla save does nothing. The Save button stays visible.
`SuppressNpcCombatReactions`	NPCs ignore gunfire: no panic, no police call, no wanted level.
`DisableVanillaPlayerDeath`	Players cannot die from weapon damage. Damage to NPCs is unchanged.

Optional: limit which other mods stay loaded with a ModPolicy.
```
Policy = new ModPolicy
{
    RequiredMods = new[] { "S1API" },
    AllowedMods = new[] { "Hotline" },
},
DefaultRequiredModsOnly = true,
```
- With a policy, Side Hustle restarts the game into a temporary profile that loads only the kept mods. Leaving the gamemode restarts into the full mod set.
- The player confirms the change first. Installed mod files are never moved or deleted.
- Names match the MelonLoader name or the DLL file name, case-insensitive.
- Always kept: MelonLoader, S1API, Side Hustle, your own mod, the multiplayer libraries, and every dependency of a kept mod.
- A required mod that is not installed blocks the launch with a message to install it.
- DefaultRequiredModsOnly preselects “Required mods only” on the Host form. The host can change it.

Check it works

Start your gamemode. The loading screen shows, then your launch callback runs in the world.
With BlockSaveDuringSession, press Save. Nothing is written.
End the session with ctx.ReturnToHub(). The menu and the hub come back.

Run your gamemode in the game world

Steps

Check it works

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