Object and gameplay manipulation in Doom 3

In order to get the most out of Doom 3's gameplay, I decided to see what happens if I push boxes and crates around, to the extent allowable by the engine, and see if I can manipulate the game engine and, eventually, break the gameplay.

So far, I found that most doors that close in order to force you into a fight, can be blocked by pushing a crate right between them. Some of the doors however will also place an invisible "uncrossable" linedef which can't be passed even if you block them or otherwise cheat and try crossing them a second time.

An example of door that normally shuts down but can be "hacked" is the one leading to a catwalk full of Lost Souls on the level where you have to replace a reactor rod. An example of door that places an uncrossable barrier once crossed is the one leading to the first teleporter chamber in Delta Labs level 2, even if "boxed".

You can also manipulate e.g. the imp stasis chambers conveyor belt by jamming them with a box, causing them to behave in weird manners like being sucked up into the ceiling moments before another one arrives and collides.

In RoE, you have much more room for play with the grabber, down to the point of jamming the skytrain with ease. Just make sure you save before you try any of these tricks, in case the gameplay is adversely affected.

I should try these.

Would this cause the game to crash?

Cool. Maybe it will spawn more interest over Doom 3 from this forum.

Maybe with some creativity Doom 3 becomes a puzzle FPS game.

It can come in handy for creating some puzzle mods.

I've jammed the train before.

Messing with games is fun.

They surely are fun. So far, I've not been able to crash the game with any of them, but a few like jamming the skytrain may hinder progress or break the gameplay, that's why I advised saving.

So far, in plain Doom 3, I've gotten away with jamming doors, machinery, even using the noclip cheat to kill Dr. Betruger and other characters before and after in-game sequences, without changing the storyline ;-)