20 Impossible Tips

[amirhuman]

Below are the top 20 key tips and tactics I have learned from playing Impossible and Ironmand modes in case these are helpful to others:

1. The first 3-5 Impossible missions are probably some of the hardest you’ll face in a full Impossible game. If you lose one of the first three missions (or lose 75% of your troops each time) then just restart the game. The first three missions really set the tempo for the months to come and it's critical to get some of your rookies leveled up to Corporal / Sergeant ASAP. Don't bother advancing the storyline at each phase (resulting in harder missions) until your troops are well equipped and have terror under control. I usually don't complete the first alien capture mission until I have at least 5 satellites up.

2. Build at least 3 Satellite Uplinks, 9 Satellites and an Interceptor at each base before you spend money on pretty much anything else and prioritize engineers until you have at least 20 of them. Panic is highly sensitive in Impossible and if you get behind you’ll lose. Aim to have 2 satellite uplinks (in total) and 5 satellites in place before the second council report (month 2). Sell all of your gray market items to do this if you have to. Prioritize Africa, then South America, then the US. Don't bother building satellites if there are less than 20 days left before a council report and don't launch your satellites until the day before the council report so you can be more strategic about which countries you want to save -- any country with panic level 5 will drop out at the council report. Remember to take advantage of adjacency bonuses by building satellites, power gens, and workshops (don't bother with labs) in square-like grids like this:
http://www.manapool.co.uk/wp-content/uploads/2012/10/2012-10-22_00004.jpg and dig for Thermal Generators if you have to -- they are well worth the additional one-time and ongoing costs.

3. The most important rules for combat are: BE PATIENT, stay in FULL COVER (or half cover with hunker down) as much as possible, and DO NOT DASH unless you're trying to prevent an Overshot. Move the first/blue move for all units, RE-EVALUATE, then make your final moves. If you do this as a general rule you will get surpise-blitzed much less often and be more in control of the battle tempo. The key to winning is POSITIONING.

4. Keep your group together when there are no visible enemies and once you have engaged enemies spread out a bit if they have grenades (and don't bother if they don't) but try not to increase your visibility / advances to new areas of the map or you will likely engage other enemy groups and be overrun. With very few exceptions (which are perhaps glitches), new enemy groups cannot attack you until AFTER you discover them and it shows their intro scene. Use this to your advantage.

5. Flank the enemy whenever possible with your assault to increase hit/crit chances and reduce enemy defense for the rest of your soldiers.

6. Execute actions in the best possible order and attack with finality -- avoid leaving any enemies standing. Check all of your troops to see who has the best shot on each visible enemy before attacking. Often the best thing to do is advance to cover and Hunker Down or Overwatch until your squad is in a good position to wipe out all enemies in one turn.

7. Take advantage of the combined skills of your troops. For example, flank an enemy with your Assault, then use a grenade to destroy the enemy’s cover, then holo-target the enemy with your Heavy, then attack with the Assault to reduce enemy below 50% health, then attack with a Sniper to leverage Executioner (increased damage below 50% health) if you have it and/or to increase the chances of In The Zone. One time I killed 5 enemies with one Sniper chaining In The Zone. If enemies are clustered, start with a Shredder Rocket to increase damage on those enemies from all sources.

8. Panic will not increase if you pass up UFO missions for UFO's that you have shot down. If your key troops are on the mend, don’t take those missions unless it's early on in the game, you can sacrifice some recruits, and you need the cash. Also if you're running the Slingshot expansion, you don’t have to run the secret operations missions – they won’t increase panic if you abandon them.

9. Don’t give up. There will probably be times when two of your main Captain/Major level troops will get wiped out in one mission. Keep fighting.

10. If you engage too many enemies at once, retreat to another location and let them come to you. Note that on UFO landing missions (i.e. UFOs that you did not shoot down), then enemies will generally come to you but otherwise they will not – you have to discover them first, so remember point #4.

11. As for Officer Training, I prioritize Squad Size 5, then Rapid Recovery, then Squad Size 6, then Increased EXP, then whatever you can get with your highest rank. New Guy will conveniently upgrade all existing Recruits.

12. Tank with your Assault. If you are going to get attacked, try to influence enemies to attack your Assault, particularly if he has Resilience. If one of your non-tank units gets exposed, expose your Assault to the enemy even more to protect your weaker units. Defense-spec’ed Assaults have more health, are less likely to get crit'ed, and require less healing.

13. Know Thy Enemy. Here are some examples: melee units (Chrysalids and Berserker Mutons) can only attack on their first move which is 8 boxes for Berserkers and 10 for Chryssalids. You can ignore cover with melee units. Sectopods do not show an alert for their Overwatch and they also can prepare a ground strike on an area that is executed the following turn -- you don't know exactly where they are targeting but the camera pans to the general area so you should clear out from that area on that turn. Sectoids' main weakness is that when you kill the hive mind host, its client also dies, so bypass the client if you can see the host and kill the host. This Wiki has good info on each enemy type and you should use the in-combat enemy profile view once you have autosopied each enemy: http://xcom.wikia.com/wiki/XCOM_Wiki

14. On alien abduction missions, prioritize the Chryssalids or you will be overrun by zombies turning into Chryssalids and lose your entire team.

15. Prioritize armor over weapons to avoid your units getting one-shot killed. Get your full squad into Titan ASAP and then Ghost ASAP and you’re pretty much all set.

16. When running troops through the Psy Lab, only run one of your mains at a time. This is the best time to use Alloy or preferably Hover SHIVs with the Plasma upgrade as subs. I often take a Hover SHIV with me on the final Ethereal missions because they hit hard, are great scouts, and are immune to mind control.

17. When you Mind Control an enemy quickly use their grenade on themselves and enemies near to them. You don't want them to survive those 4 turns, and definitely not with a grenade still in their hands.

18. Troops tend to panic more often in Impossible mode and will more often attack a squad mate if there is no enemy in sight, which can then cause that squad mate to panic and send you into a downward spiral. Be mindful of this when facing Muton-class enemies.

19. Be careful how you use your Weapon Fragments and try not to sell them. They are probably your scarcest resource, followed closely by Alloys.

20. In terms of squad composition for Impossible, I recommend not more than one Support (3 extra moves, 3 Medkits), two Heavies (both with Shredder and Rocketeer and one with Holo-targeting), and either one Assault (all defense except for Rapid Fire) and one Sniper or two Snipers (Move-and-Shoot, Opportunist, and In The Zone).

Stay frosty out there!

[sylvao]

really good topic. thanks.

[amirhuman]

You're welcome! Also I forgot to add that I think an Ethereal's chances of reflecting your attack are affected by the extent to which you are in cover, so be careful with Assaults using Run 'n' Gun to stand right next to an Ethereal or your Rapid Fire may "Back Fire".

[ronald.friedrich]

Are you absolutly sure about point 8?

[Mr Windblade]

Point 8 is accurate. Not chasing down the UFO you shot down penalizes you with a loss of the tech, not a panic raise.

[ronald.friedrich]

i mean the ignore council missions thing.

[ronald.friedrich]

Just tested. Ignoring council missions increases panic by 2.

[Segovax]

If you have already beaten the game - which IMO you should do before playing Impossible - then enabling "Not created equal" is a good way to min/max soldiers. Check the rookie stats on the first mission and if you have 3 guys with Aim of 75 to 80 with will that isn't in the dirt, you have a solid squad to work with that has a slight edge.

I've found that alloys are the really scarce material mid to late game.

I think ignoring council missions is a *really* bad idea since it eliminates a major panic management aspect. I'm pretty sure ignoring the bomb threat mission increases panic, but don't remember. By the time you have sats over everything you may be okay to ignore a council mission for the -2 Panic but by then you've assaulted the base and reduced panic world wide anyway. Additionally those resources are generally much better than the resources you receive from abduction missions (unless you randomized the rewards per Second Wave) in a situation where you need everything you can get. A council mission in months 1 and 2 can be completed with rookies, played smart, and even if you lose 3 of 4 you're going to make a net profit of $155 from the average $200 + other stuff + panic reduction reward. In fact, trading anything lower than a Sgt for panic reduction early in the game is pretty much worth it unless all your good troops are crippled and you have one guy active above Rookie.

The first 3 missions are almost always the same - mission 1 is almost always 12 sectoids, mission 2 is almost always the same, though there might be thin men thrown in, and mission 3 is always a UFO you shot down. You want to hit that downed UFO like its the girl of your dreams. It will almost, if not always have 4 sectoids and an outsider. The loot from that mission is what is going to let you pump out your second sat before the month ends. If you get an undamaged power source thats $75 right there, along side the 4 sectoid bodies, alloys and any other trash.

Ethereals ability to reflect attacks is directly proportional to their Will. If you manage to damage them enough or get lucky with an attack that drops their will, their chances to reflect the attack go way down. Since they have will bonuses on Impossible, it does increase their chance to reflect an attack.

If you find yourself flush with cash early on and feel the need to spend it, remember that a medkit prevents poison on whoever is carrying it even if it's been used. Helps with thin men.

[amirhuman]

Thanks HerrComrade for the insights on initial Impossible missions and Ethereal reflects.

I should have clarified that I downloaded the Slingshot expansion (which takes over your Council Missions) and you can definitely skip those repeatedly without affecting Panic. The first Slingshot mission isn't too hard, but the 2nd one (planting scamblers on the train in 10 turns) is quite challenging and I would not recommend attempting it on Impossible until you have a 6man squad all in Carapace+ armor and all-laser weapons.

The best thing about Slingshot is that after you have completed the Gangplank (battleship) mission, you get two Fusion Cores that can be used to create 2 non-LOS, higher-damage rocket launchers, which are a little OP.

[amirhuman]

Originally posted by HerrComrade:

If you have already beaten the game - which IMO you should do before playing Impossible - then enabling "Not created equal" is a good way to min/max soldiers. Check the rookie stats on the first mission and if you have 3 guys with Aim of 75 to 80 with will that isn't in the dirt, you have a solid squad to work with that has a slight edge.

Yeah I did that on Ironman Classic to boost my chances but wanted to do Impossible on vanilla.

[Slava Ukraini]

nice guide... I have try play on classic and If I die I shall try spend more money on Satellite Uplinks and Satellites. How many Satellite Uplinks and Satellites I need in a game? So I dont buy for much?

[amirhuman]

hotfix see point #2:

Build at least 3 Satellite Uplinks, 9 Satellites and an Interceptor at each base before you spend money on pretty much anything else and prioritize engineers until you have at least 20 of them.

[Slava Ukraini]

Originally posted by amirhuman:

hotfix see point #2:

Build at least 3 Satellite Uplinks, 9 Satellites and an Interceptor at each base before you spend money on pretty much anything else and prioritize engineers until you have at least 20 of them.

I play on classic and I think I can beat the game but how long is left I dont know. I dont know why ships never coems more so I can shoot them down but im happy them not come. I have only this interceptor and whne I try play first time thats coem a really big ship in the beginning and shoot me down so why that dont coems ships this time I play? I have made and buy the ship firestorm? But cant buy it and use it? Maybe its different between classic or impossibel but I have only ship in my country.

[PotatoeMan]

Originally posted by amirhuman:

hotfix see point #2:

Build at least 3 Satellite Uplinks, 9 Satellites and an Interceptor at each base before you spend money on pretty much anything else and prioritize engineers until you have at least 20 of them.

Don't forget to actually build and launch the satellites too. Not that I would do something like that.

Does anyone know how explosions damage/loss items?

What else should you avoid selling?

[Segovax]

Originally posted by amirhuman:

Thanks HerrComrade for the insights on initial Impossible missions and Ethereal reflects.

I should have clarified that I downloaded the Slingshot expansion (which takes over your Council Missions) and you can definitely skip those repeatedly without affecting Panic. The first Slingshot mission isn't too hard, but the 2nd one (planting scamblers on the train in 10 turns) is quite challenging and I would not recommend attempting it on Impossible until you have a 6man squad all in Carapace+ armor and all-laser weapons.

The best thing about Slingshot is that after you have completed the Gangplank (battleship) mission, you get two Fusion Cores that can be used to create 2 non-LOS, higher-damage rocket launchers, which are a little OP.

It was definitely hard but I just did it the other day on Impossible with most of the second wave settings on. I did have to reload a couple times, but my squad was 5 guys with Zhang the only guy above sgt and no upgrades on anyone. It's almost exclusively Thin Men with a couple of Mutons thrown in - the Mutons appear in the open so you can get free flanked shots on them.

Originally posted by PotatoeMan:

Does anyone know how explosions damage/loss items?

What else should you avoid selling?

Explosives destroy alien corpses and gear iirc. I am not sure if they destroy weapon fragments actually.

I only avoid selling fragments and alloys early on because scraping cash to get in a genny and second uplink asap is important. The problem with sats on impossible is you will have at least 3 countries in the red at the end of month 1 and the existing uplink only has room for 1 more sat. Generally you are going to choose which continents you don't care about in month 1 - and I think the easiest way is to start in Asia and lose a member there since you get the bonus anyway. So keeping North and South America happy is the way to go IMO, and getting full sat coverage over S America is easy - and the instant interrogation/autopsies on Impossible are awesome when it comes to crunching time.

[amirhuman]

Updated the OP based on inputs from the group, thanks.