I picked up a few more augmentation canisters during that last mission, so this is as good a time as any to explain in detail how they work.

Essentially, there are two parallel character-development systems in the game. I’ve already talked a little about skills. They’re pretty straightforward. You receive skill points for completing objectives, advancing the plot, or exploring new areas, and you can spend them to upgrade your skills at any time. With a few exceptions, they just let you use your weapons or tools more effectively.

Nan-augs are found in canisters, and are generally guarded and/or locked up. Each canister has two abilities it can grant, and you must choose between them. Each canister is also associated with a particular body part; for instance, Microfibrial Muscle and Combat Strength are appied to the arms. Most body parts can only take one upgrade, although JC can take three Torso enhancements and two Subdermal enhancements. This makes things a bit more complicated.

The Aqualung and Environmental Resistance canister I found in the last mission is a Torso augmentation. I can only use it to acquire one of the abilities (ER, in my case). However, there are duplicate canisters available later in the game, so I could in theory pick up Aqualung later. I won’t do that, though, since there are two other types of Torso canisters available, each with two associated abilities. This means there are six possible augmentations, but JC can only fit three of them in his Torso, and Aqualung is pretty much the worst of them. But if you really wanted to give JC the ability to swim for hours in radioactive sludge, you could do so.

Well, not hours, exactly. Nanoaugs aren’t always active, and when you do switch them on, they consume bioelectric energy, which is Deus Ex’s answer to mana or psi points: an arbitrary statistic that decreases when you use your special abilities. Augmentations all consume power, which you can only regain by drawing power from a repair bot, which is not portable, or using a bioelectric cell, which is portable, although they’re consumedwith use and there are a finite number available in the game. It’s a large finite number, mind you, but finite nonetheless. Naturally, the more useful the aug, the more rapidly it tends to drain power, so you can’t be Superman all the time.

In addition, each nano upgrade has four different levels. A newly-installed upgrade is at level 1, and isn’t usually that great. Microfibrial Muscle gives you a slight increase to your strength: approximately 20%. Environmental Resistance reduces your damage from toxins and radiation by 25%. This latter doesn’t sound like much, but it’s the same reduction you’d get from using a Hazmat suit if you haven’t invested any points in the Environmental Training skill. As you can see, there’s a bit of a trade-off at work. You can reduce damage with Environmental Resistance, expending some bioelectric energy in the process, or you can use Environmental Training, which requires you to use a hazmat suit (and they’re only good for a limited duration).

In order to increase the effectiveness of your upgrades, you don’t spend skill points. Instead, you use nanotech upgrade units which you can find at various points throughout the game. Each upgrade will enhance any one augmentation by one level, and naturally, they’re in somewhat limited supply. Upgrades tend to enhance your augmentation from “somewhat useful” to “spectacular.”

In cases where there’s some overlap between a skill and a nano-aug, it’s best to pick one or the other to specialize in; since skill points and upgrade items are in limited supply, you don’t really want to invest in redundant abilities. The power drain for Environmental Resistance is modest, and I’d rather not have hazmat suits taking up precious inventory space, so I’ll be relying on it throughout the game.

I’ll start by upgrading Environmental Resistance whenever I can, until it’s level 3. Each of the first three levels reduces environmental damage by 25%, so at level 3, it gives a 75% damage reduction; this is what I was talking about when I said that augmentation upgrades are important. You get diminishing returns at level 4, which grants only 90% protection. It’s certainly better than 75%, but remember, each upgrade that I spend on Environmental Resistance is one that can’t be spent elsewhere.

Such as Speed. The two leg upgrades are Silent Running (lets you move quietly while running at full speed) and Speed (which makes you faster, increases your jumping height, and increases the distance you can fall without taking damage). Silent Running sounds good for a sneaky character, by I think Speed is far better, since it enhances your mobility and allows you to jump over obstacles and into otherwise-inaccessible locations. Once I have ER up to level 3, if I devote all my upgrades to Speed, it’ll reach maximum level about halfway through the game. At that level, it nearly doubles my running speed, more than doubles my jumping capability, and allows me to fall up to 60 feet without taking damage. This is an ability with some profound tactical implications.

By the end of mission 2, even without having had the chance to upgrade my augmentations muchm, I have the ability to travel through hazardous areas with reduced damage, jump higher and farther than normal, and lift and move heavy objects. There are all good abilities for opening up new paths or navigating dangerous routes with minimal damage, which in turn makes it easier to avoid guards and security cameras. An alternative stealth build might use the Silent Running and Combat Strength abilities to run up behind guards and beat them into unconsciousness while their backs are turned. Or, instead of using Microfibrial Muscle to lift obstructions out of the way, a combat-oriented character could use it for wielding heavy weaponry and Rambo-ing his way through every enemy in the game.

The great thing about Deus Ex is that the nano-augmentations let you choose between a bunch of useful abilities, and you can utilize each of them in a variety of ways depending on your playstyle. I’m sure some combinations are better than others, but there are enough routes through the game that just about any plausible-seeming character build is probably viable.