Firaxis flipped the premise of the 2012 reboot. The aliens won, ADVENT runs Earth's cities as a friendly-looking police state, and XCOM is a guerrilla cell flying a captured alien supply barge called the Avenger. Most tactical missions open in concealment and run on a turn clock, so ambushes beat slow Overwatch creeping. Everything below covers the base game released in February 2016, with the August 2017 War of the Chosen expansion flagged wherever it changes the answer.
This guide covers everything you need: core mechanics, the best builds, equipment worth investing in, location progression, and the tips that actually make a difference.
Core Mechanics
Concealment openers
Nearly every mission starts with your squad hidden, which lets you walk all six soldiers into flanking positions and set Overwatch before a single shot goes off. Moving inside a red vision cone breaks concealment for everyone. A Ranger with Phantom is the exception, staying hidden after the rest of the team is spotted.
Mission turn timers
Guerrilla Ops and Council jobs usually allow 8 to 12 turns to hack a workstation, plant the X4 charge, or reach the evac zone. That clock punishes double-Overwatch stalling. The correct play is normally to push toward the objective and accept one messy pod activation on the way.
Avatar Project doom bar
Every alien facility ADVENT finishes adds a block to the Avatar bar on the geoscape, and a full bar starts a countdown to campaign loss. Raiding a facility strips blocks back off. Treat it as a pacing device, not a fixed deadline.
Class promotion trees
A Rookie who survives promotes into Ranger, Grenadier, Specialist or Sharpshooter at random, then picks one of two abilities at every rank up to Colonel. The Guerrilla Tactics School can train a Rookie straight into the class you are missing, and its Squad Size upgrades raise the deployment cap from four soldiers to six.
Avenger facility rooms
Excavated rooms hold the Guerrilla Tactics School, Proving Ground, Psi Lab, Advanced Warfare Center, Resistance Comms and Power Relay. Build a Power Relay on an exposed alien power coil and it produces double output, so check the Avenger layout before you commit an excavation crew.
For a deeper dive into how these systems interact, see our XCOM 2 combat guide.
Builds Overview
| Build | Tier | Playstyle | Key Stats |
|---|---|---|---|
| Ranger | A | Versatile approach | Balanced stats |
| Grenadier | A | Versatile approach | Balanced stats |
| Specialist | A | Versatile approach | Balanced stats |
| Sharpshooter | A | Versatile approach | Balanced stats |
| Psi Operative | A | Versatile approach | Balanced stats |
For full build breakdowns with gear and stat priorities, see our XCOM 2 builds guide. For rankings, check the tier list.
Equipment Guide
| Equipment | Why It Matters | Best For |
|---|---|---|
| Assault Rifle | The Ranger and Specialist primary, upgrading to the Magnetic Rifle and then the Plasma Rifle. | Specialists, and any Ranger built around the sword |
| Shotgun | Ranger only, running Shotgun to Shard Gun to Storm Gun. | Close-range Rangers who open flanks |
| Sniper Rifle | The Sharpshooter primary, going Sniper Rifle to Gauss Rifle to Plasma Lance. | Squadsight Sharpshooters parked on high ground |
| Cannon | The Grenadier primary, upgrading to the Mag Cannon and then the Beam Cannon. | Grenadiers built for Shredder, Chain Shot and Rupture |
| Grenade Launcher | A Grenadier secondary built in the Proving Ground, later upgraded to the Advanced Grenade Launcher for more range and a wider blast. | Demolition Grenadiers who need to delete cover at distance |
Assault Rifle: The Ranger and Specialist primary, upgrading to the Magnetic Rifle and then the Plasma Rifle. Raw damage is unremarkable at every tier, which is why rifle carriers earn their keep through Aid Protocol, hacking and sword kills instead of shooting.
Shotgun: Ranger only, running Shotgun to Shard Gun to Storm Gun. It hits hard inside a few tiles and falls apart at range, so it pairs with Run and Gun and Rapid Fire rather than long sight lines.
Sniper Rifle: The Sharpshooter primary, going Sniper Rifle to Gauss Rifle to Plasma Lance. Firing it costs your whole turn unless you have Death from Above or Serial, and that restriction is the central tension of the class.
Cannon: The Grenadier primary, upgrading to the Mag Cannon and then the Beam Cannon. Paired with Shredder it removes armor on every shot, which matters more than its damage number against late-game enemies.
Grenade Launcher: A Grenadier secondary built in the Proving Ground, later upgraded to the Advanced Grenade Launcher for more range and a wider blast. It turns every grenade in your inventory into a cover-removal tool you can use from safety.
Full breakdowns in our XCOM 2 weapons guide.
Location Progression
| Location | Level Range | Key Rewards |
|---|---|---|
| Guerrilla Ops | Squad of 4 to 6, from month 1 onward | Intel, Supplies, blocked Dark Events, sometimes an Engineer or Scientist |
| Retaliation missions | Squad of 5 to 6, month 2 onward | Region kept in contact, new recruits, occasionally a Resistance soldier |
| Supply Raids | Squad of 6, month 2 onward | Large Supplies payout, Alien Alloys, Elerium Crystals |
| Alien Facility raids | Colonel-heavy squad of 6, month 3 onward | Avatar Project progress removed, Elerium Cores, alien corpses |
| Avenger Defense | Every available soldier, triggered by story progress | Survival, salvage from the wrecked UFO |
Guerrilla Ops: Three missions appear at once and you pick one. The two you skip each trigger a Dark Event. Objectives are usually a hack, a VIP grab or a device to destroy, and almost all of them carry a turn limit.
Retaliation missions: ADVENT hits a Resistance haven and Faceless hide among the crowd until they transform. The mission ends the instant every alien is dead, and everyone still standing at that moment is saved, so speed protects civilians better than caution does.
Supply Raids: Convoy and train missions where you loot crates while ADVENT keeps dropping reinforcements. These are among the few untimed maps in the game, but the reinforcement flares never stop, so untimed does not mean relaxed.
Alien Facility raids: The only way to pull filled blocks off the Avatar bar. You destroy the facility power source and extract. Garrisons here are heavy enough to punish an undergeared squad badly, so bring your best six.
Avenger Defense: ADVENT finds your ship and you fight on your own hull with whoever is healthy. The objective is destroying the alien power source that keeps feeding reinforcements onto the deck. Lose here and the campaign ends outright.
See our maps & locations guide for detailed area breakdowns and our walkthrough for the optimal progression path.
Tips That Actually Matter
- Excavate toward a power coil early. A Power Relay sitting on an exposed coil generates double the power of one on plain rock, and a power shortage in month 3 stalls every other Avenger project you had planned.
- Guerrilla Tactics School before the Advanced Warfare Center. Squad Size I is the single largest tactical upgrade in the campaign, because a fifth soldier is one more action every turn for the rest of the run.
- Contact regions in the direction your Resistance Comms capacity can support, not in the direction of the story. Each contacted region adds monthly Supplies, and Supplies gate armor and weapon tiers.
- Research autopsies before you sell corpses. Tygan's autopsy projects gate several Proving Ground items, and the Black Market pays more for corpses later in a campaign anyway.
- Magnetic weapons before Predator Armor. Killing an enemy one turn earlier prevents more damage than a single point of armor absorbs, and Modular Weapons plus attachments compound that effect.
- Use a Phantom Ranger as a dedicated scout. Reveal the pod alone, pull back, reposition the other five soldiers, then trigger the fight on your terms instead of stumbling into it.
- Grenades exist to delete cover, not to deal damage. A Sectoid in full cover is close to a coin flip. The same Sectoid standing in rubble after a frag is close to a guaranteed kill.
- Keep two Specialists in rotation. Aid Protocol is a free plus 20 defense on whoever is about to get shot, and Revival Protocol pulls a mind-controlled or unconscious soldier back without burning a medkit charge.
- Do not rush the Blacksite. Yes, it drops the Avatar bar. Going in with Squaddies and conventional weapons is how campaigns die, and two extra Guerrilla Ops of experience is worth the bar segment you lose waiting.
- In War of the Chosen, keep Covert Actions running constantly. Idle soldiers should be earning Resistance orders, Ability Points and faction influence, and even the actions with a soldier capture risk usually pay off once you can field two full squads.
Common Mistakes to Avoid
- Playing Overwatch chess against an 8 turn timer. The mission fails, your soldiers still took the damage, and you get nothing for it.
- Never opening the Black Market. Surplus corpses and captured ADVENT gear are a major Supplies source, and the stock rotates monthly, so a campaign that ignores it stays permanently poor.
- Treating a Sharpshooter like a normal soldier. Squadsight only fires when someone else has eyes on the target, so a Sharpshooter who moves with the pack every turn is throwing away the whole class.
- Letting wounded Colonels heal at base speed. The Advanced Warfare Center cuts recovery time and randomly grants bonus abilities, and a healthy campaign needs about twelve usable soldiers by month 4, not six Colonels and a pile of Rookies.
- Standing next to cars. One stray shot sets a vehicle burning, it explodes a turn later across a wide radius, and the warning is right there on screen the whole time.
Frequently Asked Questions
Do I need War of the Chosen to follow modern XCOM 2 guides?
Effectively, yes. The 2017 expansion adds the Reaper, Skirmisher and Templar hero classes, the three Chosen, Covert Actions, Resistance Orders, soldier fatigue and the Lost, then rebalances enemy pods around all of it. Advice for the four core classes and the research tree still holds, but anything about mission pacing assumes you own it.
Which class should I train first at the Guerrilla Tactics School?
A Specialist. Hacking pays for itself on Guerrilla Ops objectives, Aid Protocol keeps a flanked soldier alive, and Revival Protocol answers the Sectoid mind control that wrecks so many early campaigns. Grenadier is a close second, because Shredder is your answer to armor.
How bad is losing a soldier?
Survivable if you keep a bench. What actually hurts is the lost ability points and the specific build, not the body. Rotate twelve soldiers through missions instead of six and a squad wipe becomes a setback rather than the end of the run.
Is the Avatar bar a real timer?
A soft one. Filling it starts a countdown of a few weeks rather than an instant loss, and raiding an alien facility removes progress permanently. Campaigns die from ignoring the bar for two straight months, not from letting it sit at half.
Should I play Ironman on my first campaign?
No. XCOM 2 teaches through squad wipes, and a first run on Veteran without Ironman lets you rewind and see exactly how that bad pod activation happened. Save Ironman for Commander once pod activation and timers make sense to you.
More XCOM 2 Guides
- XCOM 2 Best Builds
- XCOM 2 Tier List
- XCOM 2 Walkthrough
- XCOM 2 Beginner's Guide
- XCOM 2 Tips & Tricks
- XCOM 2 Weapons Guide
- XCOM 2 Combat Guide
- XCOM 2 Boss Guide
- XCOM 2 Maps & Locations
- XCOM 2 Crafting Guide
- XCOM 2 Classes & Characters
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