In the 90's, FPS games used the arrow keys to navigate. But around the new millennium, WASD begins to take over the arrow keys, and a few year after, every FPS game use WASD for navigation. Today the WASD-keys are also in use in other game genres, such as some platformers - and even beyond games, the WASD-keys are in use for navigation, as you also can use WASD to navigate in Google Earth!

But I would like to ask, who invented the WASD controls for FPS games? Was it Half-Life, Quake, or an other game/game developer?

Was it not Quake that made it popular?

Popular, yes, but I think Marathon on the Mac was the first one to use it to any real effect.

According to Wikipedia, Quake was the one to popularize it.
As for first game using such a control scheme, seems to be [url=http://en.wikipedia.org/wiki/Moria_(PLATO)]Moria[/url], though it was W for forwards and A/D to turn left/right.

Not sure who invented WASD, but I do understand the need to 'use keys on the left side of keyboard for comfort', out of necessity.

I thought you was meaning, who set up the letter layout on standard keyboards... all I know is it has to do with math and how often a letter comes up in typing and its placement (and other variables, like be on different hands for faster typing speeds) I allways use a/d to strafe :P and mouse to turn.
<3 quake 1, I remember playing it in school on Macs... I hated only having one mouse button to no end)

I'm perplexed, because the first and last PC FPS game where I remember using arrow keys to navigate was Wolfenstein 3D (1992). Ever since Doom, I moved to using WASD-like setup (they weren't exactly WASD keys, but more like ZXCV or ASDF, similar idea anyway), mainly because Doom wasn't anymore restricted to alt-strafe like Wolf3D was.

I did use arrow keys also on Doom, but not for moving around, but turning left and right. Some others already used the mouse for that in Doom, but I didn't like that because at least back then moving the mouse forwards/backwards moved you also forward/backward in the game, and I didn't find a way to disable that (and still keep mouse for turning). Maybe this was changed later in Doom, because I recall sometime playing it with a mouse, without that glitch.

Duke3D was the first FPS game where I started using mouse for aiming. After all, it was the first pure FPS game where I recall seeing up/down aiming with mouse support, unless you count something like Ultima Underworld where aiming was done with a cursor moving on the screen.

I remember first using it in Half-Life. In Quake the defaults were arrows, in Half-Life it was WASD

My personal experience started with Quake. Before then I don't really remember using a mouse for aiming. So arrow keys were the norm.

I pity anyone who still uses that set up! :P

I remember it first in half life as well before then i think it was always arrow keys by default.

Same for me. At first in HL I was like "WTF is this setup?" but then I realized how useful it was.

LOL XD
Wasn't it: Wonderful - Arrows - Substitute - Definitely ? :P

From a pure usability perspective, WASD was a suboptimal choice though. You can't find the keys blindly since none of your fingers rests on a nubbed key, you can't use your pinky for additional commands (at least only very few), and for many games and gamers it feels more ergonomic to have index, middle, and ring finger all on the same row.

Personally I use FDCG for movement, and all keys around those have identical functions in most games. Meaning, X is always my reload key, W is always my map key, U is always my light key, etc., in all games I play which allow individual key configurations. But I'm probably quite mad, so ... ;)

Back in the old days, before we used the arrow keys in games (and indeed before we used mice for almost anything), Z was left and X was right.

Ultima Underworld was not WASD exactly, but they were the progeniter of the control scheme.

I'm pretty sure it was the same guy who put the bomp in the bomp bah bomp bah bomp, and who put the ram in the rama lama ding dong.