Insurgency: Sandstorm game modes and mods

An Insurgency: Sandstorm server runs one game mode at a time, chosen by the scenario name in the launch line or the map cycle - Scenario_Hideout_Checkpoint_Security is Checkpoint co-op on Hideout as Security. The decision that shapes everything else is co-op or PvP: co-op modes (Checkpoint, Outpost, Survival) are capped at eight humans and their load comes from bots, while PvP modes (Push, Firefight, Skirmish, Frontline, Domination and others) take up to 28 players. On top of that you can stack the shipped mutators with -mutators= for free, and add mods through mod.io, which the server downloads itself once it is authorised. Pick the mode for your group size first, then mutators, then mods.

The install, Game.ini basics, admins, RCON and ports are in the Insurgency: Sandstorm server guide. This post is about what the server plays: each mode and who it suits, how scenarios are named, building a cycle that mixes them, what the mutators actually do, and running mod.io content without breaking the server.

Choosing a mode for your group#

The modes are not interchangeable flavours. They need different player counts, cost different amounts of CPU, and attract different players.

The single most important fact on that table is the eight-player cap on co-op. It is hard-coded; setting MaxPlayers higher on a co-op scenario changes nothing. A Discord of twenty who want to play co-op together needs three servers, not one bigger one. A group that wants everyone on one server needs a PvP mode, or Checkpoint with friendly bots filling the gaps.

Co-op is also where the server's work happens. Every enemy bot is simulated on the server's game thread, and Checkpoint scales bot counts between MinimumEnemies and MaximumEnemies in the [/Script/Insurgency.INSCoopMode] section of Game.ini. A co-op server with those values raised is heavier than a full 28-player Push server. If a co-op server stutters in firefights, look at the enemy count before the plan. What tick rate actually means explains why one busy thread decides how the whole server feels.

Scenario names and how to find them#

A scenario bundles map, mode and side into one token: Scenario_<Map>_<Mode>[_<Side or layout>]. The map part is the display name (Hideout, Refinery, Crossing), not the internal level name used in the travel URL - the mismatch between the two is covered in the main guide.

Scenario_Hideout_Checkpoint_Security     Checkpoint, players as SecurityScenario_Hideout_Checkpoint_Insurgents   Checkpoint, players as InsurgentsScenario_Refinery_Push_Security          Push, Security attackingScenario_Crossing_Skirmish               SkirmishScenario_Farmhouse_Firefight_West        Firefight, western layoutScenario_Precinct_Domination             DominationScenario_Bab_Survival                    Survival

The side suffix means different things per mode: for Checkpoint it is the side the players are on; for Push it is the side that attacks. Not every map has every mode, and NWI adds maps and scenarios in updates, so do not build a cycle from memory. The server will tell you what exists:

scenariosscenarios Checkpointscenarios Hideout

The scenarios command (also answered to maps) lists every scenario the server knows, filtered by whatever text you give it. Run it over RCON or from the console after each game update and build your cycle from the output. A scenario name that does not exist is skipped in the cycle, and a launch line naming one fails to start.

Map cycles that mix modes and lighting#

Insurgency/Config/Server/MapCycle.txt is the rotation, used when bUseMapCycle=True in [/Script/Insurgency.INSMultiplayerMode]. The simple form is one scenario per line. The tuple form lets each entry override lighting and mode, which is how one map becomes several distinct rounds:

(Scenario="Scenario_Hideout_Checkpoint_Security",Lighting="Day")(Scenario="Scenario_Refinery_Checkpoint_Security",Lighting="Night")(Scenario="Scenario_Crossing_Checkpoint_Insurgents",Lighting="Day")(Scenario="Scenario_Hideout_Checkpoint_Security",Mode="CheckpointHardcore")(Scenario="Scenario_Farmhouse_Checkpoint_Security",Lighting="Day")

What makes a cycle work:

• Do not mix co-op and PvP in one cycle. The player counts and the audiences differ. A PvP server that suddenly travels to a co-op scenario kicks everyone above eight; a co-op group dropped into Push with nobody on the other team has a bad evening.
• Ration night. Night rounds with night vision are distinctive and divisive. One in four or five is a good starting ratio; if the server empties on night rounds, you have your answer.
• Use the hardcore override deliberately. Mode="CheckpointHardcore" on the same scenario gives a harder round without a second map in the list. Interleave it for a group that asks for it rather than running a whole hardcore cycle on a public server.
• Check after updates. Scenario renames break cycles silently.

If you keep several cycles - a weekday co-op cycle and a weekend event cycle - select one with -MapCycle= on the command line and keep each as its own file. Swapping cycles is then a startup parameter change and a restart, which on a panel is one field on the Startup tab.

For live changes, travelscenario <scenario> moves the server immediately, and travel <map>?Scenario=<scenario>?Lighting=Night gives full control over one round without touching the cycle.

Per-mode settings#

Beyond the shared sections, each mode has its own Game.ini section named after its game mode class, following the pattern [/Script/Insurgency.INS<Mode>GameMode]. The Checkpoint section is the one most servers tune:

[/Script/Insurgency.INSCheckpointGameMode]DefendTimer=90RetreatTimer=10RespawnDelay=20CounterAttackRespawnDelay=20

Counter-attack timing is what makes Checkpoint feel frantic or measured. Longer defend timers with fewer enemies produce a slower, more tactical game; short timers with high MaximumEnemies produce a horde shooter.

Rather than trust any list of keys - including this one - ask the server. Over RCON, listgamemodeproperties prints every property the current mode exposes, and gamemodeproperty <name> <value> changes one on the running server. That is the right way to tune: change a value live, play a round, keep it or put it back, then write the winner into Game.ini so it survives a restart. Live changes are lost when the server restarts.

Mutators: free variety with no downloads#

Mutators ship with the game and need nothing from players. They change rules for the whole server and are enabled on the command line:

-mutators=Hardcore,HeadshotOnly

Several can be combined with commas. The shipped set has grown over updates; the commonly used ones include:

A few observations from running them:

• Mutators are for events, not every night. Frenzy on a Friday is memorable; Frenzy every round empties a server within a week.
• Combinations interact. HeadshotOnly plus BulletSponge is pointless; Hardcore plus BoltActionsOnly is a legitimate niche server. Test combinations before announcing them.
• Mutator settings live in `Engine.ini`. The official server guide notes this inconsistency; if a mutator's tuning is ignored, check which file it is in before anything else.
• Mod mutators work the same way. A mutator delivered by a mod.io mod is enabled by name in the same -mutators= list once the mod is installed. The mod's page gives the exact name.

On a panel host, the mutator list is a startup parameter, so changing the event of the week is editing one field and restarting.

A weekly event pattern

A pattern that works for co-op communities: run the normal Checkpoint cycle all week, and on one fixed evening switch to an event configuration - a different cycle file selected with -MapCycle=, a mutator or two, perhaps night lighting throughout. Announce it in your Discord a few days ahead with the exact rules, and switch back the next morning.

The mechanics are simple and worth getting right:

1. Keep the event as its own cycle file, so the normal cycle is never edited.
2. Change only the startup parameters for the event - the cycle and the mutators - then restart.
3. Use a scheduled restart to switch back at a fixed time, so nobody has to remember.
4. Take a backup of both config trees before the first event, so a mistake costs one restore.

Events built this way are cheap to run and give regulars a reason to come back on a particular night, which matters more to a small server's population than any setting. Scheduled tasks worth having covers the scheduling side.

mod.io mods: maps, mutators and overhauls#

Sandstorm's mods come from mod.io, not the Steam Workshop. They fall into three kinds:

• Maps with their own scenarios, played by travelling to the mod's map and scenario names.
• Mutators, enabled with -mutators=.
• Overhauls that change weapons, factions or rules across the game.

The current server workflow registers the server with mod.io and manages its subscriptions on the mod.io website. The first launch passes an emailed security code, every later launch uses -SecurityCode=none, and -mods enables mod support. The full launch syntax and the older token-based scheme are in the main Sandstorm guide; the operational detail that matters here is what happens at each start:

-ModDownloadTravelTo= names the map and scenario the server travels to once its downloads are done. Point it at the first round you actually want played, not a test map, or every restart starts on a scenario nobody chose.

To play a mod map, you need two names from its mod.io page: the map name and at least one scenario name. Put them in the cycle like any other scenario, or travel to them directly:

travel ModMapName?Scenario=Scenario_ModMapName_Checkpoint_Security

Mod authors choose these names, and the page is the authority. Watch the log on the first travel; a misspelled name fails the travel and the server stays on the current map.

Keeping a modded server stable

• Mods update when their authors publish. The server picks up updates on restart. An update that breaks a map breaks your cycle the morning after a restart, with no change on your side. Keep a list of what is subscribed and when it last changed.
• Players must have the same versions. Clients are prompted to get the server's mods when they join; a player whose download fails cannot join and will blame the server.
• Fewer mods attract more strangers. Each mod is a download standing between a new player and the first round.
• Stats and XP are an official-content feature. A server built around mods should not promise progression; check the current NWI rules for whether a particular mod or mutator affects stats eligibility before advertising XP.

When a game update lands, update the server first, then check each mod has been updated for the new version, and drop any that have not from the cycle. What to do when a mod update breaks has the general playbook, and keeping a modded server clean the argument for a short mod list.

Sizing by mode#

The plan you need depends more on the mode than on the player count.

Disk grows with mods: each mod map adds to the cache, and old versions linger until cleared. Keep headroom for an update, when old and new files briefly coexist. On RE:NODE the console graphs show CPU against the limit live, which is the fastest way to see whether a new mutator or mod map is what pushed the server over.

Troubleshooting#

More than eight players cannot join co-op. That is the cap; no setting changes it. Use PvP or run a second server.

A scenario in the cycle is skipped. It was renamed or never existed. Check with scenarios.

The server starts on a test map after every restart. -ModDownloadTravelTo= still points at the mod test map. Point it at a real scenario.

A mutator does nothing. Its name is misspelled, or its settings are in Game.ini instead of Engine.ini. Mod mutators also need the mod installed.

Mod maps stopped loading after a restart. An author published an update that is broken or renamed a scenario. Read the log, then check the mod page.

Players disconnect while downloading mods. A large mod set or a slow mod.io download on their side. Trim the list.

Live tuning reverted. gamemodeproperty changes last until restart. Write them into Game.ini.

FAQ#

What is the best game mode for a small Insurgency: Sandstorm group?

Checkpoint. It is built for up to eight players against bots, scales enemy counts with the number of humans, and can be made harder with the hardcore override or mutators as the group improves.

Can I run co-op and PvP on the same server?

Not sensibly in one cycle - co-op is capped at eight and PvP expects many more. Run two servers, or switch cycles with -MapCycle= and a restart for scheduled events.

Do players need to download mutators?

Not the shipped ones; they are part of the game. Mutators from mod.io mods are downloaded like any other mod when players join.

How do I list every scenario my server can run?

Use the scenarios command over RCON or the console, optionally with a filter such as scenarios Push. It reflects the server's current version and installed mods.

Why did my modded server break without me changing anything?

A mod author published an update and the server picked it up on its last restart. Check the mod's page and changelog, and keep a list of subscribed mods so you can remove the broken one quickly.

How many bots should a Checkpoint server run?

Start with the defaults and change MaximumEnemies live with gamemodeproperty during a real session. The right number depends on your group's skill and on how much CPU the server has, so tune by playing rather than copying a value.