The split is not where people expect it. Nearly everything you touch in a Horde Siege mission is in the story mode too, under the same names and on the same buttons. What does not carry over is the money.
What carries over
The game states it in one line:
In the game’s words
“Supply Caches can be found throughout the Campaign, Horde Siege, and Combat Training. Use them to adapt as the fight evolves.”
Three modes, one object. Everything below follows from that, because the Cache is where loadouts, equipment and weapon mods all live.
Campaign against Horde Siege
A dash means nothing has been published either way. It never means the system is absent.
| System | Campaign | Horde Siege |
|---|---|---|
| Supply Cache | Yes. Refills ammo, changes your loadout and fits weapon mods. Xbox Wire | Yes. Also where Energy is spent. |
| Tactical Gear | Yes. The demo offered a choice of two. Xbox Wire, Game Rant | Yes, and your class decides which one. |
| Weapon mods | Yes. Rewarded for optional side missions. Game Rant, Xbox Wire | Yes. Bought with Weapon Parts. |
| Hardcases | Named on Tac-Com next to Caches and Collectibles. | Named as a source of armor mods. |
| Side objectives | Optional. Two were played. Game Rant | Sixteen, offered to the squad by name. |
| Collectibles | Yes, with their own menu and a music cue. | — |
| Energy | — Never described in the campaign | Yes. The shared wallet. |
| Squad Perks | — Never described in the campaign | Yes, from side objectives and Invasions. |
| Classes | You are Marcus alone, or one of Bravo Squad in a four-player lobby. Xbox Wire | Four, thirty levels each. |
| Getting out | Checkpoints. The game tells you to load an earlier one when you are stuck. | Extraction, and what you earned is lost if you miss it. |
Rows that name no news outlet are the game’s own wording. Rows that name one come from a writer who played the campaign in August 2026.
The Cache remembers what you did last time
The description is the one Horde Siege players already know:
In the game’s words
“Access Supply Caches that have been placed throughout the city to customize your loadout and re-fill your ammo. Use Tac-Com to track nearby Cache locations. Each time you find a new weapon it is added to the Supply Cache inventory. When you access a Cache, both its inventory and your loadout are saved.”
Two rules under that matter more across a campaign than in a twenty-minute mission. “Picking up a new weapon or piece of equipment unlocks it permanently in the Supply Cache.” The stock list grows as you play, so a gun you find early is a gun you can ask for later, and that is a kind of progression Horde Siege has no room for inside a single mission. And “Your equipment set up is always saved after you exit a Supply Cache”, so walk out with the one you want.
The line to remember is the third one: “Get back to a Supply Cache whenever you can to get your fully modded weapons back.” Mods are attached to your weapons, not to you. Pick a Hammerburst off a dead Drone and you are carrying a stock Hammerburst. That is fine for a fight and bad for a chapter.
Xbox Wire describes the campaign Caches doing that job: dotted around the city, used to refill ammo, change loadout and fit weapon mods. The game also tells campaign players to “use Tac-Com to find Collectibles, Supply Caches, and Hardcases”, which puts all three on one button.
Who picks your Tactical Gear
The definition does not change between modes. Tactical Gear is “a rechargeable item that can be deployed [...] to affect enemies or give you and your squad advantages in combat.” Own button, no cost, comes back on its own.
What changes is who chooses it. Horde Siege is blunt: “Each Class has its own Loadout and Tactical Gear.” Take the Medic and you are running the Stim Vaporizer, and there is no second option. In the campaign demo, Xbox Wire and Game Rant were offered a choice between the Injector, which applies Adrenaline, and the Sonic Disruptor.
Two of the four, in one demo, with no class attached. Whether the Stim Vaporizer and the Pulse Drone show up as well, and how you get them, is not published.
Mods come off the side missions and nothing else
The game names two ways a mod arrives, and neither is the main route. Weapon mods: “Find Hardcases and finish Secondary Objectives to unlock new Weapon Mods and Mod Slots.” Armor mods: “Armor Mods can be found in Hardcases around the city or earned by completing Secondary Objectives.” Both are detours, and the main objective is named in neither.
Game Rant played that loop in the campaign. Two side quests in one chapter, both flagged as completely optional, and players who finish them “will be rewarded with helpful weapon mods”. The two it names are defending a car dealership and freeing a family trapped in a convenience store. The mods it and Xbox Wire came away with are damage buffs and a reload on a chainsaw kill.
Skipping side missions does not mean skipping flavor text. It means skipping the only source of mods either mode names, so you can run the critical path from the first chapter to the last and finish it carrying stock guns.
The mod goes on at the Cache and stays on: “Customize your weapons at Supply Caches. Each time you modify a weapon it is saved with that configuration.” The mod index lists what the game names. No mod publishes a price, a percentage or a duration.
What stays in Horde Siege
Three of the systems people assume travel are written about one mode only.
Energy. “Use energy at the Supply Cache to buy Weapons, Equipment, or upgrade Squad Perks.” A Horde Siege sentence. No preview describes being charged for anything at a campaign Cache, and whether the campaign has a currency at all is not known.
Squad Perks. “Earn Squad Perks by completing Secondary Objectives and Invasions.” Invasions are a Horde Siege event, and the twenty-seven perks have never been mentioned outside that mode.
Weapon Parts. The wording is explicit: “Earn and Extract Weapon Parts from missions in Horde Siege.” They only count if your squad escapes the mission, a Horde Siege rule covered in everything you can still lose at the Raven. The campaign runs on checkpoints, so that gate cannot work the same way. How the campaign pays for a mod slot is not published.
The rest of Horde Siege’s features go on the same list: three squads on one map, the R.I.G. objectives, the mission modifiers, poisons and Invasions. None of it has turned up in a campaign description.
What the campaign has instead
The traffic runs both ways. You can play it offline. “Campaign and Practice Space can be played offline if installed. Versus and Horde Siege require an online connection.”
Difficulty is yours alone. “Set the difficulty of your desired Campaign Experience. Your difficulty can differ from others in your game.” You can also “switch difficulty any time from the pause menu”, and on Casual you can pick yourself up off the floor without help.
Collectibles are a campaign list. “Collectibles you find in the Campaign will appear here.” They come with a tell the game hands you outright: “Pay attention to a sudden music stinger, there might be a Collectible around.” Game Rant found two on a stretch of bridge, a damaged helmet and a pair of Locust sniper goggles.
What is not published
Four things, and they are the ones people ask about.
How many side missions there are. Two were played, in one chapter. No total has been published, so there is no number here.
What anything costs. No campaign price for a weapon, a mod or a piece of Equipment has been shown. The game does list currencies to spend: Coins (sold in bundles), Iron, weapon parts and Perk Points. Weapon parts have their own balance display on screen, and Coins have a similar one; none is shown for Iron or Perk Points. Separately, a Treasure Chest system hands out weapon and equipment unlocks without a purchase. Character skins, weapon skins and profile customization are listed alongside those currencies, which suggests a store exists to sell them. Nothing settles which currency buys which item, or what anything costs. The game’s own text lists Iron packs of 300, 500, 1,100, 2,300, 6,000 and 13,000, and the Premium edition includes 1,000 Iron. What those packs cost in dollars, and what any skin costs in Iron or Coins, is shown only in the in-game store and is not published.
Whether armor mods are a campaign system, from press coverage alone. The wording names Hardcases and Secondary Objectives, and the campaign has both, but no previewer mentions armor mods. That was suggestive, not a source, until the released game settled it. They exist: 20 Armor Mods plus 48 more across four Special Gear items, with numbers for 23 of the 68. See the list of all 68 campaign mods.
Any figure at all. No damage value, no cooldown, no blast radius, no mod percentage, in a campaign preview or anywhere else. The weapons page carries what the game states.
Sources: Xbox Wire, Danielle Partis · Game Rant, Dalton Cooper · TheSixthAxis, Dom Leighton · The Coalition, Multiplayer Deep Dive. Anything not attributed to one of those is the game’s own wording.
See also: All 140 campaign collectibles.