Reality… as basement gods know it.

[Part 1/x of the World building for dummies series.]

Game worlds are not MeatSpace simulators.
As obvious as it sounds, this basic truth about the nature of games seems too often lost on the most myopic nerds among players and MMO designers alike.

It's easy to understand the urge: lots of insanely cool/scary/exciting/epic stuff has happened through history, or could have happened, had history been willing to go just at tiny bit differently to fit our personal preferences, misconceptions, and power-fantasies.

— Think about it for a minute, dude: if Albert Einstein had been born Japanese instead…

— Of course ! Nukular rocket-riding Ninjas would rule the world ! Maan, how cool would that be ?

— Amen… I tell you, those Nazis really ruined it for us.

For better or worse, game worlds are teleological, designed to serve a purpose rather than the consequence of such fun-agnostic principles as the laws of thermodynamics and special relativity, thus the best can happen when designers fully embrace their god-like role, with the attached responsibilities of keeping internal consistency and making the universe interesting for its mortals.

Teleology is for the worse when game designers miss the point of 'fiction' and try their best at making a 'realistic' game world, based on their limited understanding of how reality works, which they take to be a valid guiding rule to achieve a consistent design — not only does it fail to produce anything remotely verisimilar, it practically guarantees the only places the game will successfully emulate reality will be at its most uninteresting.

— Do we seriously have to roll a check for Mildly Uncomfortable Bowel Movement at -7 on every combat round ?

— Doh… yeah: it would be Unreelistic not to !

The very worst case — and most common — scenario happens when game gods get bitten by the "But I'm one on TV !" bug, and start believing in their own infallibility — a faith they will defend in the face of contrarian facts with any shaky rationalization they can muster, under the delusion that coming up with lousy excuses for a sloppy job magically un-lames the results.

— Nukular rocket-riding Ninjas !

— Er… no-nonsense ancient Greece setting, here ?

— Ain't that a great mystery for the players to solve, then ?

Yes, if it sounds like fan-fiction, that's usually a good indication the design sucks.