Zero hit and minimal hit
Posted July 13th 2013
Basics
For the purposes of this article, by a 'hit' I mean an incident in which you or your vehicle incur even the slightest damage through enemy or friendly action or your own combat clumsiness (e.g. rocket going off too close) or an accidental fall, or any incident in which you lose health - which includes being killed of course. The challenge of 'zero hit' is to get through the entire level without taking a single hit, and with no reversion. A pretty tall order, and one which makes the lesser challenge of 'zero health loss' seem almost like a walk in the park! In regard to the "no reversion" aspect, that's partly to prevent someone reverting quick when they think they're about to get hit. That would be a cheap escape indeed, and we don't want that. You're going to have to be mighty careful throughout the level, and even a small slip could mean game over.
Note that 'hit' doesn't include taking shield damage from a deliberate fall, a grenade or rocket jump, a vehicle jump, flames, or scripted events such as in the disabling of generators in Two Betrayals. So there's not a total ban on damage; just on instances which relate directly to combat or foul-ups, you might say. You've still got a bit of leeway when it comes to manoeuvring, as long as you keep things well controlled.
Of course, you can also do zero hit in conjunction with any other rules you care to impose. In my case that typically means the rules of my kill 'em all speed runs, and I might apply weapon or vehicle restrictions too.
When on foot or in a Warthog or Scorpion or Shade, damage is usually easily noticeable from your shield bar. If it drops even slightly, that's damage. When in a Ghost or Banshee it's potentially harder to notice if you don't lose a vehicle health bar, but you'd get vibration feedback if it's turned on.
Viability issues
There's at least one level in which zero hit probably isn't fully viable, namely The Maw, where I think hits would be pretty much impossible to avoid in the section where you're blowing up the vents (the game repeatedly ambushes you with Sentinels), and also on the timed escape phase. Really I need to review such cases so I can say where I think it's appropriate to suspend the zero hit aspect (though there would still be no reversion allowed), so you can at least still enjoy attempting zero hit in the viable areas. I'll see about that later. However, the first five levels are certainly ok.
Minimal hit
In the event that you take a hit, you could switch to the secondary goal of at least trying to minimize the number of hits while getting through with no reversion - something I'd term 'minimal hit' play (a form of play based on a performance measure). That would still be a worthy goal after all, and could be taken as your main aim during a phase of honing your technique - assuming you do have aspirations of eventually managing a zero score. The rule here is that as soon as you take a hit, you're not allowed to kill again until your shield is recharged; and the whole thing just adds 1 to your hit count. Typically then, you'd retreat to safety until recharged and ready to venture forth again.
Tactics
For zero hit, you'll really need to think about how to deal with things. Time for a bit of tactical chat!
Stealth and safety
Stealth and safety are the order of the day, and you'll undoubtedly find yourself developing new techniques for handling certain areas, as conventional play will often be too risky. Distance is your friend and ideally you'd want to be out of enemy range, unless confident about some close-up stealth work. Try not to be under threat from more than one enemy at once, particularly if they're in significantly different directions. Keep the danger limited by good positioning, and be cautious even of Grunts and Jackals, especially on Legendary where they can open fire in a flash.
Never even saw me
When you're obliged to be within range of possible enemy fire, the safest thing is if they never get a chance to shoot at all. Keeping a close watch on your motion tracker will help for starters; you really want to know where enemies are, to avoid getting surprised. Tagging an unsuspecting enemy who'd be risky to try creeping up on is a great way of getting rid of him. There's also the possibility of killing an enemy the moment he comes into sight, before he has time to react. As far as Grunts go, a pistol is good for that. For Jackals, you might prefer using a plasma ball to get rid of the shield first; and they'll also get stunned of course, allowing you time for a follow-up. Mind you, it's generally good not to be too close to enemies when they die from your gunfire, as there can be a danger of getting hit by death throe fire.
Tight cover
When enemies know you're there, you can often use very tight cover to make it hard for them to get a line of fire at you; and if a shot does come your way, your dodge to safety need only be minimal, thus reducing the likelihood of taking a hit. You could even be firing from a position where their shots probably can't get you. That typically involves having an obstacle in front of you, just low enough to allow you a line of fire. Finding good positions of tight cover is one of the main things you'll probably be doing in honing your technique.
When stealth goes wrong
If you go creeping up on an Elite at close range, it's worth having a plasma grenade ready. If you're suddenly spotted, tagging him can prevent him opening fire while you quickly get to cover (though he may still manage to get a shot off after he's finished growling, so you'd better be safe by then). Using a plasma ball is another option, for the way it stuns.
Bozo trouble
Generally speaking, Marines are a liability, not just in the way they'll wreck any stealth work but also for how they act as magnets for enemy fire which could then hit you, plus you could be hit by friendly fire of course. I wouldn't kill them off myself, unless some fool is heading straight for me on a Ghost and I've got a rocket launcher handy, but I sure don't mind letting them get killed off by the covies. That would make one less thing to worry about. One way Marines can be of use however, is in providing a distraction, as long as they're not close to you.
My progress
In this evolving section I'll document my progress with the challenge.
AOTCR Legendary kill 'em all, on foot
Thus far I've only actually been trying zero hit with AOTCR, my favourite level. Specifically I've been trying it on Legendary on foot, with the rules of my kill 'em all speed runs. After many attempts (going back more than a year) I finally managed it, taking about three and a half hours.
I set a good pace in the first half of the level, reaching the first tunnel door (leading to the cavern) after about 27 minutes, and going through the door in the area with twin bridges overhead after about 65 minutes. In the remainder of the level I got a lot more slowed up though, sometimes giving myself lots of time for patient stealth work in tricky rooms, of which there are plenty. I had a few close calls along the way, and in the final octagonal room (the one with two cloaked Elites, after coming down in a lift) I almost fragged myself when a hastily thrown grenade bounced off a wall and came back my way. I'd been trying to locate and kill a Jackal, and suddenly found him. There was also a notable event along the way. In the cavern I killed two Hunters with a single sniper round! It entered the stomach of one and passed through to the back of the other just behind him. Can't remember sniping two at once before.
Prior to my success, the best I'd managed was to get through with only two hits, something I did twice. All incidents involving taking a single shot from a Grunt or Jackal due to slight carelessness - which just goes to illustrate how it's not only the Elites you need to worry about. There was also a time when I got almost to the end with no hit, and then when I opened the door at the top of the pyramid structure, I dawdled too long lobbing grenades through the opening, and took a needle in the back as I attempted to hightail it up the tower. You can imagine how happy I was with myself after all that work, when I was almost there. Arrrgh! If you ever attempt zero hit yourself, "Arrrgh!" will be a very handy phrase to remember.