How to Unlock More Weapon Mod Slots in Gears of War E-Day

TL;DR – Key Takeaways

• Every weapon starts with Slot 1 open. Slots 2 and 3 are locked by default.
• You can unlock extra mod slots in the Campaign by finding yellow Hard Cases and completing Secondary Objectives.
• Hard Cases are not available in Act 1 — slot progression begins in Act 2.
• In Horde Siege, mod slots unlock by leveling up your Siege Class.
• Mods and slots are separate — unlocking a slot does not auto-equip a mod.
• Always return to a Supply Cache after opening a Hard Case to register and equip your reward.

How Weapon Mod Slots Work in Gears of War E-Day

Every weapon in Gears of War E-Day has three numbered mod slots. When you first pick up a gun, only Slot 1 is open. Slots 2 and 3 show as SLOT LOCKED until you actively unlock them.

Unlocking a slot and unlocking a mod are two different things. You need both before you can actually equip something. Once a slot opens, head to any Supply Cache, highlight your weapon, press X to Modify, pick the slot, and press A to equip a mod.

There’s also a Perfect Reload row on every weapon’s mod screen — that one is separate from the numbered slots and works a bit differently.

For a full look at every weapon in the game, check out our Gears of War E-Day All Weapons List.

How to Unlock More Weapon Mod Slots in Campaign

In the Campaign, there are two ways to unlock extra weapon mod slots: opening Hard Cases and completing Secondary Objectives. Both reward mod unlocks and sometimes extra mod slots tied to specific weapons.

Find and Open Hard Cases (Yellow Containers)

Hard Cases are yellow COG crates scattered through the campaign maps — away from the main route, so you have to explore a little. They look different from green Supply Caches. Open one and gold banners pop up naming each reward.

Here’s the important part: opening a Hard Case doesn’t immediately give you the reward. The game will prompt you to get back to a Supply Cache. Until you do that, the new slot or mod is not registered on your weapon.

Use Tac-Com (hold LB) to mark nearby Hard Cases on your screen so you don’t miss any.

A few important things to know about Hard Cases:

• Act 1 has no mod slot unlocks. Act 1 does have Hard Cases, but none of them unlock additional weapon mod slots. Slot progression starts in Act 2.
• Hard Cases are tracked separately from Collectibles — opening them does not increase the Collectibles counter on your map.
• Finding all Hard Cases in the Campaign unlocks the Relax achievement.
• Some chapters are one-way. Grab nearby Hard Cases before major transitions or you’ll miss them permanently.

Key Hard Case Locations That Unlock Mod Slots

Below are some of the most valuable Hard Case locations across the campaign that directly reward weapon mod slots:

• Act 2, Chapter 2 – Hold the Line: This is the richest chapter for mod slots. You can open 16 Hard Cases on one route. Notable rewards include a General Mod Slot for the Hammerburst (near the Bank of Tyrus vault) and multiple Injector and Disruptor Mod Slots.
• Act 2, Chapter 3 – No Gear Left Behind: More Hard Cases that continue the mod slot chain from Chapter 2.
• Act 2, Chapter 5 – Overrun: The vehicle depot side bay holds a Hard Case that gives a General Mod Slot for the Gut-Puncher.
• Act 3, Chapter 1 – Stranded: Additional Hard Cases open up here for further mod and slot unlocks.
• Act 3, Chapter 2 – Enemy Lines: A Hard Case on the subway platform rewards an Injector Mod Slot, Pulse Drone Mod Slot, and mods — four rewards in one case.
• Act 4, Chapter 1 – Hope and Ruin: A Hard Case in the hotel lobby gives a General Mod Slot for the Lancer Mk1.
• Act 4, Chapter 3 – Tough as Nails: Hard Cases here reward General Mod Slots for both the Longshot and the Incinerator.

Want detailed weapon-specific guides? Check out our guides for the Lancer Mk1, Gnasher, Hammerburst, Incinerator, and Longshot.

How to Unlock More Weapon Mod Slots in Gears of War E Day

Complete Secondary Objectives

Secondary Objectives are optional side missions tucked into the larger open-district chapters. They reward weapon mods, armor mods, tactical gear mods, and sometimes extra mod slots you won’t get anywhere else on the critical path.

Walk to the marker on your map, hold X to start the objective, finish the task, and claim the reward. Here are some that specifically unlock mod slots:

• Special Cargo (Act 4, Chapter 3 – Tough as Nails): Rewards a General Mod Slot and Expanded Magazine for the Longshot.
• Trapped Locust (Act 4, Chapter 3 – Tough as Nails): Rewards a General Mod Slot and Spring-Loaded Mag for the Incinerator.
• Several other Secondary Objectives in Act 2 and Act 4 reward mod unlocks even if not a direct slot — these let you fill the slots you’ve already opened.

Use the map (View button) to track Secondary Objectives. The legend uses separate icons for active, completed, and failed ones. Don’t let them fail — some are time-sensitive once started.

Check out our complete Secondary Objectives guide for every location and reward. Also see our Act 1 Walkthrough and Act 2 Walkthrough for full routing help.

How to Unlock Weapon Mod Slots in Horde Siege

In Horde Siege, the mod slot system works completely differently from the Campaign. Here, slots are tied to your Siege Class level — not exploration.

Horde Siege has four classes: Assault, Breacher, Marksman, and Medic. Each class has its own 30-level progression track. As you level up, the track unlocks weapons, mods, extra mod slots, and Tactical Gear for that class.

For Tactical Gear mod slots specifically, the unlock levels are:

• Level 2 — Unlocks 1 Tactical Gear Mod Slot
• Level 9 — Unlocks 2 Tactical Gear Mod Slots
• Level 16 — Unlocks 3 Tactical Gear Mod Slots

Weapon mod slots on the class track follow a similar structure — keep leveling and they open up along the way.

A few key things to know about Horde Siege mod slots:

• Unlocking a mod on the class track doesn’t give it to you for free. You still need to buy it with Weapon Parts.
• Weapon mods are shared across all classes for the same gun. So if you unlock a Hammerburst mod on the Assault class, it’s available on Marksman too.
• Weapon Parts mainly come from completing Secondary Objectives in Horde Siege missions, class-level rewards, and Weapon Part Stockpile pickups on the map.

See our Best Builds for All Classes and All Tactical Gear List to plan your loadout around the slots you unlock.

Tips to Unlock Weapon Mod Slots Fast

• Prioritize Act 2, Chapter 2. Hold the Line is packed with Hard Cases — 16 in one chapter. Hit this chapter thoroughly and you’ll unlock multiple weapon slots in one run.
• Always use Tac-Com (LB). It highlights Hard Cases nearby. Don’t rely on bumping into them by accident.
• Don’t leave a chapter without visiting a Supply Cache. Hard Cases do nothing until you register them at a Cache. Make it a habit to stop at every green crate you see.
• Do Secondary Objectives as you go. Don’t save them for later. Some are in time-limited combat scenarios, and you can fail them if you wait too long.
• In Horde Siege, grind one class at a time. Spreading XP thin across all four classes slows everything down. Pick your main class and push it to at least Level 9 to get two Tactical Gear mod slots quickly.
• Farm Weapon Parts in Horde Siege. Even after a slot unlocks, you need parts to buy mods. Secondary Objectives inside Horde missions are your fastest source.

Also check out our guide on All Mods List to know what to slot in once your slots are open.

Where to Equip Weapon Mods After Unlocking Slots

All mod equipping happens at Supply Caches — the green COG resupply crates throughout the Campaign.

Here’s how to do it:

• Walk up to a Supply Cache and interact with it.
• Highlight the weapon you want to modify and press X to Modify.
• Select a numbered mod slot and press A to Change Mod.
• Choose your mod from the list and press A to Equip Mod.
• If the mod conflicts with one already on the weapon, you’ll see a prompt to Replace Conflicting Mod.

Your weapon keeps its mod configuration from that point forward. Each weapon is saved with its setup — you don’t have to re-equip every time you pick one up.

If you’re looking for the right mods to pair with specific weapons, our guides on the Prototype Lancer, Torque Bow, Gut-Puncher, Ripper, and Breechshot all cover mod recommendations in detail.

For everything else about the game in one place, visit our Gears of War E-Day Complete Guide Hub.

Frequently Asked Questions

Where to Play Gears of War E-Day:
Official Gears of War Website | Xbox Store | Steam