If you find yourself among strange men the surest way to get a conversation going is to talk about shaving. Men love to talk about shaving. Likewise if you find yourself among parents of infants you can't go wrong with poop.
Before I became a parent I knew in a vague way that I'd be dealing with a lot of dirty diapers. What I didn't realize is the scrutiny with which I would examine them, like an augur poring over entrails. Babies have very few communication channels so you take what you can get.
For the first few days you get diapers that look like Vegemite. After that, if the baby is breastfed and there aren't any problems, you get diapers that look like either Dijon or French's mustard. We recently diagnosed a problem with the way we were feeding our baby from the green, frothy appearance of her output.
Enough about that, though; I can tell you're bored already.
I sent off a copy of my little Thief/Rogue hybrid to an old friend this weekend. He's been playing my half-creations since we were teenagers. I got back some keystroke logs and watched to see how things went.
He commented that he found the Ctrl-direction system of using things somewhat cumbersome. When you attempt to move into a closed door, you get a message on the status line that says something like “Press Ctrl+left to open the door.” Pressing the key combination opens the door; you can press it again to close the door. I also require “use” style movement when entering terrain types that hide the player (water, tables, bushes) because I thought people might be confused if their player icon disappeared. The bump messages serve the purpose of identifying things in the world, too. You can bump into anything usable and see what it is: a torch, a switch, a window, a portcullis, etc.
I already have a problem with teaching the player about the different ground types, since there's no way to bump them. Any solution I come up with for that could probably be applied equally well to water and bushes, and probably for crawling under tables as well.
Doors (and windows) are a bit more of a problem. The close-door action is already hidden; you have to use the empty door space so you don't get a bump message for it. If I make doors automatically open when you bump them it will make the close-door action even more hidden since it won't be symmetric with opening. Also, I'd need to preserve the bump message and use for locked doors since I don't think players would want to automatically enter the lockpicking minigame. Also, I am not sure how key use would fit. I was thinking of having the game automatically use the correct key on a locked door, but indicate in the bump message which key would be used.
Other random thoughts:
Doors could close themselves when you move away from them. I think this would take out some fun, though. At the moment I have locked doors lock again when you shut them, so you're committing to another lockpicking session when you shut a door. (Most doors only lock from one side, so you can freely open them from inside.) On the other hand, I've planned to make guards suspicious of opened doors, so closing a door would help keep you from being caught.
Door opening is a risky action. There might be someone on the other side, or light might spill out and illuminate you. This is part of the reason I've got it as an action distinct from basic movement.
Alternatives to the Ctrl-direction key chord method of using:
1. Bump-then-use. In this scenario you would be required to bump something to put it into ready-to-use state; then you'd press a single key (numpad Enter, say) to use the thing you'd targeted. This is nicer in that you press a key sequence rather than a key combination. However, it does require you to get bump messages for things. The biggest loser for that is door-closing. Perhaps door closing could be handled by generating a bump message when you enter the square containing the open door? It would say “Press Enter to close the door.” If you pressed Enter, the door would close as soon as you moved off of that square. If you did anything else I guess it would cancel the door closing. It's not ideal since you don't get immediate visual feedback that the door has closed; it's more like you're putting your hand on the door and pulling it shut as you move.
2. Omnidirectional use. This would work similarly to bump-then-use except you wouldn't have to get a bump message first. When you press the use key, if there is a single usable object adjacent it uses that. If there are two or more you'd be prompted for a direction. I really don't like this because behavior is different in different contexts, which means it won't be something that can be committed to muscle memory.
3. Special keys for using things. This is the grand Roguelike tradition, with several pages' worth of commands for doing various kinds of actions. You could have a “close door” command, an “open door” command, a “light lamp” command, etc. etc. I dislike this because I don't feel that making all of these actions into distinct keys really adds anything to the gameplay. If it was done in order to reduce the number of keystrokes required that would be defensible; but in most cases they could be collapsed to fewer distinct keys without adding any ambiguity.