The testing process has already changed one of the game's most fundamental systems since we last saw it. The game is set in a world where cybernetic implants are possible but controversial. You're injured early on, and saved by augmentations installed without your consent.
From then on, it's up to you how much of your body you replace with cybernetics. Originally, the idea was that you'd have to visit a Limb Clinic in a major city and pay in-game currency to get a new augmentation installed. You'd be able to upgrade it in the field, with experience points earned, but you wouldn't be able to get new ones without going back to a clinic.
"We've modified it since last time," says Anfossi. "As we went through playtests we discovered that players hardly had a chance to get to the augs, because Limb Clinics are not all over the place. So we went back to the drawing board."
"It's not totally different," Anfossi continues, "but it's more flexible I would say. So right now the way it works is: you still earn experience points, and when you have a certain amount of XP that is turned into Praxis points. These points are used to purchase the augmentations, and when you have enough of them you can purchase upgrades and augs anywhere, on the fly.
PRAXIS MAKES PERFECT
"You can still go to a Limb Clinic when you are in cities, and when you get there you can buy items that refill your energy bar and things like that. You can also buy Praxis software, and you can use this software to upgrade abilities. So you can turn the money you earn into augmentations as before. What the new system does is give you more choice; you can think 'Shall I keep this money to buy a weapon that I won't find in the world, or useful things like that, or do I want to access these augs?'"
There's even a third way to get them: "In the game world, as you explore, you can find Praxis software which kind of plays a role similar to the canisters in Deus Ex 1."
Those were basically an aug-in-a-box: find one and you could install the augmentation for free. There are 21 augs in total, but most have a bunch of different functions to be unlocked. Those functions are laid out like an RPG skill tree for each aug, where spending Praxis points on one upgrade leads to others. With all those taken into account, the number of distinct functions you can add to your body and mind shoots up to 54.
When we ask the team for an example of one aug that can be specced in different ways, Anfossi thinks legs. "With the leg augmentation, the first one allows you to jump higher, but now you can go either to the right side [of the upgrade tree], which lets you do cool stuff when you land, like knockback enemies, or you can go down the left path which makes you run faster and so on."
The interesting difference between this and the original game is the concept of investment. In Deus Ex, you almost never spent anything on augs - most were found, or given as mission rewards, and provided only one choice: which of these two predefined options do you want?
In Human Revolution, every aug in the game is available to 'buy' from the start. They have varying costs, and you'll need a lot of experience to get some of the more effective ones, but you have much more freedom about how to build your character. Where Invisible War simply scrapped the original game's skill system, Human Revolution is going in the opposite direction by expanding it - under the guise of augs.