How To Decorate Like A Boss?

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That's also true of course! In fact, you may sometimes even have to make those walk spaces a little bit bigger than they would normally be, since a player character is basically a walking cylinder that can't move around obstacles as nimbly as you could in real life.
Say, for example, you're having the player walk through an airplane or a train, where there's already very little space by default. You might want to add a bit of space there to avoid him get stuck all the time.
(Unless of course you're going for a sense of claustrophobia...basically, every rule can be broken as long as you know why it exists and have a good reason for breaking it! ^^)