What I’ve been trying to say, and I can only speak for myself of course, is that it usually is VERY clear whether some trick, feat, quirk or whatever is in fact an INTENTIONAL part of the game/engine or rather a more or less unfortunate by-product of something completely different.
Here’s an example (based on a simplified interpretation of the Quake3 engine):
Problem A: Players can pass through each other like the other person is a ghost.
Solution: Player models become solid but moving obstacles so it is no longer possible to pass through each other … unless somebody gets slain. It wouldn’t be very fun if living players were constantly tripping over the bodys of their fallen comrades/foes, so when someone dies, their body turns back to the intangible but visible ghost-like being.
Intended Effect: You can no longer pass through each other making the unrealistic ghost-like feeling disapear 
Unintended Effect: Since the only difference between a stone wall and wooden wall in programming terms is the texturing, one player can position himself in a doorway and until that person moves or is slain the door way might as well be solid wall (a very unsportsmanlike behavior in document maps like mp_beach)
Problem B: Maps are 3 dimensional where not only can players run forward, backwards, left and right but also up and down. This means every movement/animation of each character needs to have another dimension added to all the basic movement (the angle of the foot when moving on tilted surfaces, the lifting of the knees in different ways when moving on stairs, etc etc etc), thus making the game 100 times more resource demanding and ultimately making it unable to run on any machine available for sale today.
Solution: Model animations stay the same but the entire model is simply being elevated or lowered in tiny intervals, thus making it seem like the third dimension has indeed been implemented.
Intended Effect: The game is still playable on mainstream computers (well, you know what I mean :D) and the third dimension does seem to work correctly.
Unintended Effect: Since the third dimension isn’t actually implemented properly at all, the famous “Clipping” problems are abundant throughout FPS games. A typical situation is where a character is standing sideways on a tilted surface and to others it appears that one of his feet is buried in the ground while the other is floating in midair (or one is correct and the other is airborne). The same applies to the character standing extremely close to the edge of a vertical drop … in very bad cases it appears that he is standing in a relaxed position but only outmost parts of one of his feet is actually touching the ground, the rest of him is floating in this air.
Now let’s combine the 2:
Unintended combination Effect: With the solid and unpassable player models, it doesn’t really matter whether you try to “go through somebody” from the left/right, front/back OR top/bottom, thus it doesn’t matter whether you try to run/walk through a person or try to pass through another person on a ladder for instance. The player model is a solid object as long as the player is alive, from all directions. The simulated third dimensional movement axis and the following “Clipping” problems means that the surface upon which one character is trying to stand can be extremely small compared to the size of the character model. And so was born the jumping/standing/crouching person on top of another person.
I know the examples were rather crude and simplified but it actually is the whole Human Ladder thing in a nutshell. It was never INTENTIONALLY created by the developers as a feature in the engine. It was an unfortunate by-product of something else and I must have missed the class when Playing within the limits of the game became Let’s exploit every loophole, quirk, mistake or even bug that we can possibly find and then say: “If it’s in the game, it must have been put there by a reason” or “If I don’t use it somebody else will” or (my personal favorite)“You can just do it too”
That’s it for me for now.
Cheers :drink:
but perhaps that’s the mappers job, not the coders ?
