When playing video games, we tend to be more adventurous than we are in real life. Most people wouldn’t even jiggle the handle on a mysterious door in the subway. Joe Bronx, on the other hand, well he’s been a mob hitman for 20 years and he’s not afraid of what’s behind that door. Joe reaches for the handle and… what?! It’s like this door isn’t even here! Did someone paint a door here?
All too frequently we’ve encountered doors-as-art. They look like a way to go or a place to explore, but once your character tries to interact with the door they find that it’s only some model or decal pasted onto the wall. Disappointing! Some games have tried to remedy this. If you walk up to a door and attempt to open it, you’ll get a message like “This door is locked.” While this solves the doors-as-art problem, it still disappoints the players. They really wanted to see what’s behind that door. Maybe, they’ll even become sidetracked looking for a key to the door that can never open. It doesn’t seem like this is a good solution, either.
So what can be done? You might try expanding the door message to something like “This door is locked. I doubt I’ll find a key.” Well, players don’t read the words you write. That’s not their fault, it’s mostly ours; brought on by years of banal kidnapped princess stories with no depth. You could play a little door knob turn sound effect and have the character say “Doesn’t look like I’ll ever find a way into here.” The player might get the point, but he or she might also get tired of hearing your character say that - especially if you’re in a long corridor of locked doors. You might not even have a voice acting budget. That leaves you with a door knob turning sound. This is actually a suitable solution for some games. Locked doors that the player actually needs to get through can be accompanied by a message to the in game objective system, or a pop up graphic on the screen, indicating that a key is needed.
It’s possible to get more creative. If you’re in an office building, there can be security cameras around that alert the security personnel that you’re trying to open office doors you don’t belong in. Depending on how upstanding the office is, security guards will come to yell at you or to shoot you. This is acceptable if you’ve given the player a clear location they must go to. A waypoint, or the front desk clerk telling you to go to conference room 2A will do. Asking the player to navigate a maze of doors where one leads to their goal and the rest lead to a game over screen is poor design. This, and many other easy to conjur solutions, add a little more depth than the locked knob sound effect.
There is another time where game designers are forced to put boundaries on the game world that must limit the player’s curiosity. These are invisible walls. Typically used in outdoor settings where the player feels like they can explore infinitely, invisible walls are needed to settle the conflict between curiosity and the realistic constraints of time, money, and level design staff. Many years ago, the player would simply walk into a literally invisible wall and wonder why they couldn’t push any further. This has become almost unacceptable today. Some sort of barrier is typically placed at the invisible wall, offering at least some explanation as to why the player can’t go this way.
It’s time to upgrade our barriers, however. The biggest culprit is water. Whenever there’s a beach, there’s bound to be an invisible wall about 50 feet past the water line. Even AAA games like Halo 3 are guilty of this. If the entrance is small, park a boat or military watercraft to block the way. If it’s large, consider using a “deserters will be shot” countdown or fog. Fog actually makes players feel like they are still moving when they’re just running into your invisible wall. Once they turn around they can exit the fog almost instantly.
The next offender is implausable barriers. These are things that the player does not believe would stop their in game persona. In the recently released Lost game, there was a pile of plane crash rubbish piled at the edges of the beach. My character can stand toe to toe with a mysterious murdering smoke monster, but he can’t climb over 2 feet of rubble? Does anyone really think Gordon Freeman can’t climb a chain link fence? Is there a single video game character that would actually respect the yellow police “Do not cross” tape? Fixing these is actually pretty easy. You can make the barrier really high and unclimbable, like by using even MORE plane crash rubbish. No one wants to climb a chain link fence that has barbed wire at the top. Police tape is much harder to cross when there’s a police man standing there threatening to detain you. It’s not fair to expect the player to cut you slack simply because it’s a game. Don’t just give the player a reason not to cross your barriers; give their in game characters a reason as well.