In terror missions, where I'm expected to save as many civilians as possible, I'm having a difficult time actually getting to the civilians in time. By the time my guys have cautiously moved up, I've lost 4 or 6 civilians.
Am I essentially supposed to have my units sprint each turn to cover as much ground as possible? If so, doesn't that leave my units pretty much open for attack? Is there some general strategy I'm not seeing for these missions?
Terror missions are somewhat unique in that you can get a general idea as to where the aliens are by where the civilians are dying - you can see the civilians even in the fog of war, and the aliens will be attracted towards them. During the alien turn you can also hear them screaming when they die - the camera tends to snap towards the civilians that are under attack.
Typically there are at least one group of chryssalids in a terror mission, which means that if you leave them alone for long enough, you're going to have big problems on your hands. Chryssalids also have no ranged attacks, which means that cover isn't a huge benefit against them.
My suggestion would be to try to move as fast as you can while still maintaining your defenses - if you don't have any idea where the aliens are, explore a couple of different directions early in your turn, while being ready to fall back if you encounter a particularly powerful alien group.
Remember that Assault troopers with Run and Gun can sprint and overwatch on the same turn, which can be powerful. Likewise, Support troops can get a boost to their ability to move without sprinting, which can make a difference. Snipers with squad sight should get to a vantage point early and try to inflict heavy damage as soon as possible.
Finally, don't neglect saving civilians, even if they're in an area with no aliens currently. Just moving within one square is enough to immediately remove them from the game. You don't need to cover their escape. This reduces the number of potential zombies/chryssalids and can keep your overall mission rating up without much effort.
Don't overemphasize the importance of saving civilians. There are 3 categories on terror missions. If you can get 2 excellents on aliens killed and squaddies lost, it really doesn't matter too much if you get a poor from civilians killed.
What you really need to avoid, especially early, is the disaster missions where you wipe or at least lose multiple highly ranked soldiers. This can happen fairly easily if you go charging in trying to save civilians and suddenly get swarmed by Chryssalids.
Basically, I would go slightly out of my way to save a civilian, but not much. It's just not worth getting a soldier turned into a zombie to save a civilian. This means that I might sprint every once in a while, but mostly I play normally.
I'm playing on classic difficulty, ironman on. I usually approach with the normal, defensive overwatch-stretches. If I do see a few chryssalids I might very well charge in to try to finish them off quickly. Just one getting away, turning civilians into unfriendly little things, is dangerous and might mean the wiping of the entire team. 6+ activated chryssalids is usually a recipe for disaster until much later in the game.
One more pointer: Bring lots of explosives on terror missions. If chryssalids manages to kill a civilian, it takes a turn for the transformation to happen. Hitting it immediately after with a grenade or rocket not only hurts it, it also destroys the body it just fed on. Problem solved easily. Since they haven't got weapons on them, no weapon fragments are lost by this approach, so the safeties on those alien grenades generally sits a bit more loose on my terror missions :-)
Sprinting and ending up with a dead soldier for your troubles is a bad choice. Do not consider the civilians as being that important: the enemy kills them, that's bad. The enemy kills you, that's bad. You kill the enemy, that's good. No or less aliens means an easier claiming of civilians.
Do not underestimate snipers here, especially if you can toss those nifty "I see you" sucker bombs :P
Killing the enemy as prime goal saves more civilians. But they are randomly placed, so do not expect you can save all at every terror mission. Save your troops, kill the enemy, then save the civilians.
Once you are far enough into the game to buy ghost armour I equip the entire team with ghost armour. That way you can sprint with impunity. I start by ghosting up the entire team and rescuing as many civilians as possible. Ghosting doesn't stop you from sending civilians off to the ship or expose the soldier. Avoid over-watch when ghosting, as the last thing you want is to have your soldier reveal them-self once the aliens start moving. Though no attacks are possible while ghosting mind control doesn't count as an attack. Effectively you replace all the civilians in an area with ghosted soldiers. With no civilians in sight the aliens don't tend to do much during their turn. At the start of your turn you are well positioned to kill off the aliens in the area. On normal difficulty I usually loose 0-3 civilians without any soldier actually getting shot at.
I frequently leave the civilians alone if they are slightly in front of me. A chryssalid will frequently ignore my troops to attack a civilian and remain exposed afterwards, and my troops are harder to replace. Sometimes, this is also the difference between an enemy that remains hidden for a turn, and one that sprints in order to end the turn next to a civilian.
I sprint if I don't think overwatch will help. This usually happens if a sniper or slower solder is toward the rear of my group and sprinting into the middle, or if they are withdrawing from the front due to injury.
Well, yes, I've pretty much arrived at the same conclusion as you: in terror missions, even if it's counter intuitive, you have to sprint as quickly as possible. Here's some points on this:
Sprint towards civilians (as opposed to empty space or various covers). Sadly, the civilian is the best cover: if when you get close to it, aliens pop around, they'll mostly shoot at the civilian and not you. This way you're pretty well "protected" and you get the best chance of protecting the civilians.
terror missions usually (actually, quite often, from what I've seen) have pretty weak aliens, as compared to what you'd currently get in other type of missions. I've had non-terror missions with gallons of mutons and cyber disks, followed by terror missions where there were only floaters, chryssalids and other aliens of the around-5-hitpoints variety. This also makes sprinting in preferred in this type of missions.
lastly, while of course, you might initially get killed if you sprint TOO MUCH in terror missions, once you get snipers with the "in the zone skill" you're pretty much safe. Due to the fact that most terror missions aliens are one-shot-kill for a well equipped sniper, combined with the fact that said aliens will usually sprint for the civilians instead of staying under cover, will result in a "in-the-zone" sniper killing up to 5-7 aliens in one turn if you drop him in their midst. In the 2nd part of the game I've had 2 snipers with "in-the-zone" and I've finished some terror missions in 2 turns (on normal difficulty) just by running them as far as possible.
and also, it helps to have support soldiers with good medical skills, such that they can carry 3 med kits each, and heal well when they use them, for obvious reasons.
