How am I supposed to defeat three codexes and three archons, and three heavy robots without using counted ammo like grenades and not being hit? I'll need grenades and medkits it the last fight, and this is not the last fight. I can put one archon to stasis, dominate second archon, try to hack one of the heavy robots (~70%), set both of my heavies to overwatch. But obviously, it is not enough.

Update: i'm asking this question because of final mission. Enemies will respawn in the final fight, so i must conserve ammo and medkits, otherwise i will be overwhelmed by packs of codices, cryssalids, mutons, those big daddy suits etc etc.

  • 2
    I wonder, even though it's a name, should the plural of Codex be Codices?
    – user37332
    Commented Feb 14, 2016 at 11:24
  • I think the general answer is "don't get into this situation in the first place". You can handle a fight where the enemies slightly outnumber your squad, but not if they're hard-to-kill enemies like archons and codexes. Commented Feb 14, 2016 at 11:51
  • Related: "Is there anything I can do to stop a Codex from cloning?"
    – Philipp
    Commented Feb 14, 2016 at 11:54
  • Are you asking for tactics against Codices or for this specific fight in the final mission? Commented Feb 14, 2016 at 12:14
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    "set both of my heavies to overwatch" - what? Why? After the fight has already started, that's one of the least productive things you could possibly do with them, even if you're conserving your consumables. And why are you triggering 9 enemies at once before the final showdown, anyway? Commented Feb 14, 2016 at 23:56

4 Answers 4


If you're intent on conserving consumables for the final fight, you need to get maximum use out of your other abilities. There's no timer here so, unless you have something Hacked or Mind Controlled, you can wait for 5 turns to let everything recharge.

If you know where the enemies are, take your time and position your squad before the fight. You want everyone in the right places (ideally spread out as all your enemies have devastating aoe attacks) so when your first move triggers the pod, the rest of your squad start killing.

Better still, locate the pod with a stealthed ranger or a battle scanner.

Don't put your grenadiers on overwatch. Ever- they're awful at it. If you want to avoid damage, they need to be proactive and start taking down enemies. Ideally they should use a cooldown-based cannon ability; you haven't mentioned their builds but opening with chain-shot, rupture, or saturation-fire will get you kills and deal with the mecs armour.

Snipers should either open with serial and should finish everything that ends up low on health or should use killing zone. If they are a gunslinger, use every ability they have to dish out all the damage you can. I can't stress enough that the fewer enemies there are at the end of the first round, the less damage you will take.

Specialists are best off opening with support protocol followed by hacking a MEC. It'll draw enemy fire and this way it can't shoot you.

The Avatar itself is monstrously powerful. It also has potentially limitless regeneration so while it's not indestructible, you can place it near the frontline (behind cover of course). You should also consider using rift instead of mind control- it can destroy multiple targets.

Finally, find something better for your psion to do than Stasis. Try to get kills with something destructive or use inspire to give the avatar another action.

If you still can't win, you may need to re-evaluate your stance on using consumables. You're not supposed to be able to clear difficult fights without them and a single flashbang or EMP would make this fight significantly easier.

  • +1 Good advice all around, especially the part about consumables. I regretted not bringing along mindshields or flashbangs as soon as I got to that final room.
    – Wipqozn
    Commented Feb 17, 2016 at 12:23
  • @Wipqozn aye, ditto. I've never bothered with mindshields because Sectoids are easy to kill (and I've never met an Avatar that's I've allowed ot live more than one turn until that point).... and I stopped carrying Flashbangs around the point at which I could reliably oneshot sectoids and vipers.... Both may make a reapparence on my next attempt :-)
    – Flyto
    Commented Apr 20, 2016 at 19:02


Psi units

Psi units can dominate one unit per mission. Use this ability to dominate a powerful unit, such as an Andromedon, or a gatekeeper if you have encountered this unit. This serves two purposes:

  • You can use this unit to deal more damage, or attack more units
  • You can push this unit forward to tank some damage, preventing that damage from being dealt to your own units

Psi units also have access to the null lance, a powerful psi attack that deals damage to a small straight line. Psi units can also open a rift in a circle that deals damage, and will make some of the units panic (deals more damage too) and some of them mind-controlled (will deal damage too). The mind control will not last long, but will make the enemy units focus on taking out that unit. Isn't it wonderful?


You can set up a sniper to take an overwatch shot against units that move in a certain cone of fire. This allows the sniper to shoot 3 enemies. The serial ability allows the sniper to fire multiple shots as long as those shots kill the enemy. This too allows the sniper to kill three enemies if set up properly.


Set up your rangers with the untouchable perk and the perk that allows you to move the unit after a kill. The first shot against this unit in the enemy turn will deal no damage. Use the ranger to flank an enemy, murder it, then move the unit to a place where it will likely only be shot once. You can use the rapid fire ability to more or less guarantee a kill.

Heavy units

Heavy units can fire a grenade and then shoot if they have the salvo perk. If they have the holotargeting perk it makes it more likely for your other units to kill the units they target. Heavy weapons remove a lot of armour, making other attacks also more useful. Finally, if you equip them with the W.A.R. suit, you can use plasma cannons to deal a lot of damage in a straight line, or shredder cannons to deal a lot of damage in a cone of fire, while also removing armour.

General tactics

Archons have three attacks. They have a melee attack, which is painful. They can shoot a plasma bolt at an unit, which is painful. And they can use blazing pylons, which they are likely to use if they can target multiple units with it.

Codexes can teleport, which will not trigger overwatch of units, and have two attacks. They can fire their gun, or they can open a rift over some units which will disable their primary weapon, but deals no damage whatsoever. They have the annoying habit of multiplying though when damaged, so you should try to one-shot them, or leave them alone until you can deal with them.

Heavy robots can shoot your units, use melee or they can use a powerful grenade attack.

In general though, you likely can not kill them all in one turn. Your assessment that "you need the grenades in the last fight" is also somewhat void. You need to use grenades whenever there is a group of enemies that you need to deal damage to, or need to remove armour of. When you realize that you might get overwhelmed, you'll need to use distance to your advantage.

Focus on getting the number of enemies down. Look at your units and determine how much damage you can likely do. Targets that are closer to you are more dangerous. Targets that need to do a double move to do damage to you can wait until the next round. Move your units in such a way that you can deal damage to the units you want to deal damage to, and other units that might want to attack your unit have to take low-chance shots or have to double-move to get into better positions.

In your case I would probably try to get the heavy MEC's to low health with a shredder cannon, then use a void rift to finish most of them off. Alternatively you can use a ranger and some sniper fire. Focus on the archons next. One of the is probably going to use blazing pylons, which you can move away from. The second one probably tries to do damage, either by shooting/melee or by going into overwatch.

If too many enemies are in range, do a full retreat. Try to get the units into better positions and let the enemy move towards you. They either cluster up, and you can use AOE to do a lot of damage, or they come in waves, which you will have a better chance of killing. You usually should avoid triggering this many units to attack at once.

Good luck, commander.

  • Yes, but in the final mission we have a special psi unit which can dominate many times with 100% success rate, but for 4 turns only. Commented Feb 14, 2016 at 11:54
  • In that case you might have gone into the final mission with a team composition that is not good at dealing with large groups of enemies. Or you are reckless and dashed forward even though there is no timer whatsoever.
    – Sumurai8
    Commented Feb 14, 2016 at 12:48
  • I've got a feeling that challenge level grows independently over time, so if i complete all researches/proving ground projects, the game will eventually become unbeatable after september maybe. Commented Feb 14, 2016 at 12:55
  • I completed it on the 3rd of november, after having completed pretty much everything. Using 2 magi, 1 heavy with W.A.R. and a shredder cannon and acid bombs, 1 support, 1 ranger and 1 sniper, plus the extra unit. The final room is somewhat hard to hold, but by that point I had an Andromedon, a gate keeper and a psi zombie to divert the enemy. I never pushed much further than the initial statue. (steamcommunity.com/sharedfiles/filedetails/?id=623628843)
    – Sumurai8
    Commented Feb 14, 2016 at 13:16
  • 2
    I found it very helpful while playing to put magazine upgrades on my snipers. They have the most difficulty actually getting to take a shot because of the limited mag size and having to spend both actions, so being able to put off reloading is very useful, especially if combined with the Kill Zone ability - I went into the final mission with two sharpshooters rocking superior scopes, magazines, and repeaters. They'd come out of kill zone with rounds to spare and absolutely obliterated oncoming enemy groups. In one instance the use of Serial allowed one to kill seven enemies (6 + 1 pistol).
    – Carcer
    Commented Feb 14, 2016 at 20:13

It's very simple, really. I've just finished Ironman Commander and what I did was open up with the Commander Avatar's Void Rift (which is huge and deals damage both at the beginning and when it collapses) and then pluck the rest with the rest of my squad.

It also helps if you use Haywire with a specialist to take down a random mechanized unit for a couple of turns (don't bother trying to control them, since you might make things worse) or using Mind Control (although you want to leave this for the Gatekeepers or Andromedons).

I'd then just regroup, recharge guns and wait until the commander's Avatar could re-use the Void Rift again before advancing to the next pod. Also, since you're limited in grenades you should invest in PC's that increase your aim, at least have a holo targeting Grenadier and have others with Heavy Ordinance and experimental ammo (preferably AP, Talon or Bluescreen rounds, in that order).

Keep the heavy weaponry and grenades aside. As you said: you want to keep them for last.


Use and abuse the Avatar. He can take a lot of damage, as he self heals. He can dish out a ton of damage with Void Rift, and he can mind control even the most powerful units with 100% success.

Use a phantom Ranger to scout, find the groups while they are together, and Vpud-rift them from far away

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