Like almost everyone else I know, when I heard about the Fatigue system, I unleashed a stream of profanity so immense it tore a hole in the space-time continuum and Captain Kirk popped out and I had to spend 2 weeks hunting him down to send him back where he belonged.

The common understanding of Fatigue, due to S-E's bad explanation skills: "After 8 hours of play, the amount of experience you gain starts decreasing exponentially. After 12 hours, it drops to zero. Fatigue resets once per week, so if you want to play more than 12 hours per week, go get WoW.

This is how I understood it. I, like many MMO gamers, sometimes play for more than 8 hours in one sitting on a weekend.

How it actually works: Time does not directly factor into it. S-E determined the amount of experience points the average gamer would get in an hour, and set this amount of experience as a "threshold." After 8 of these thresholds, experience gained starts to drop. After 15, it reaches zero. Fatigue resets every Sunday. BUT fatigue cools down any time when you are not actually levelling, at the same rate it increases. So for one, if you're soloing (and FFXIV is marketed as more solo-friendly than FFXI), it will take significantly longer than 15 hours to hit the fatigue cap. Furthermore, the very instant you go into passive mode, the cooldown starts. Next, each class has a separate fatigue gauge. So you can level your Gladiator for 15 hours, after which your physical level will no longer increase--then you put away your sword and pull out a staff. What's your fatigue level at for the Conjurer class? Zero. You can play another 15 hours if you want. Your physical level will not increase, but your Conjurer skill will.

Why does this make FFXIV better? Simple. FFXIV's multiclassing system. Once you gain a skill, you can continue to use it even if you change to another class. You're intended to multiclass. If you want to be a dedicated healer, for example, you want to be using skills from the Conjurer and Thaumaturge trees. Fatigue will encourage players to play other classes while waiting for their fatigue timers to cool down, which will lead to characters better equipped to react to whatever situations they find themselves in.

To put it in FFXI terms, imagine this: You've just reached level 41 as a red mage and are ready for a change (or your fatigue gauges are full). You then unlock the Blue Mage job. You are now a Level 1 Blue Mage with Refresh. Not to mention the HP, MP, and physical stats of a level 41.

So what happens if you're in a party and you hit the fatigue limit? So what? To use the healer example again, you're in an awesome party as a Conjurer, playing as the main healer. You hit your limit. Just to make it seem so severe, let's even say your Thaumaturge fatigue is near maximum. Pull out a sword and you're now a Gladiator with full access to all of your healing magic and MP. Continue healing as before, not one jot less effective.

So who, really, does Fatigue hurt? Hikkikomori and RMT who play in shifts. Nobody else.

In case my explanation is subpar, have a look at the following Youtube video which explains it better than me & S-E put together: YouTube - FFXIV Tactics: Understanding the Fatigue System

Yes, I know, it looks like a Wendy's training video--but the information is still good.