You wouldn’t know it from looking at it, but I am standing in front of a wall in this shot. That nice gentle slope before me is, for some reason, completely impassable. I have run afoul of my life-long nemesis: the invisible wall.
Graphics in games exist for a reason. They serve as a short-cut; a quick, visual way to convey to players what once took direct explanation or description: what options are available to them. Instead of having to explicitly state “obvious exits are NORTH, SOUTH and DENNIS”, you can instead portray this information with an image, showing instead of telling players that there are exits to the north, the south, and Dennis.
Invisible walls are a compromise between art and design. Artists want to create beautiful vistas, believable terrain, and bountiful surroundings. Design cannot always accommodate these goals; even with our rapidly expanding technological capabilities, we still fall far short of the processing power possessed by the universe. Our limited machines simply cannot contain the vastness of the world. Artists have more ability to represent the world in static form than game engines possess the ability to render those worlds. Thus we have matte paintings, distance fog, and, yes, invisible walls.
Both matte paintings and distance fog can be used to great effect in games. Mass Effect (the original, not those shooters masquerading as sequels) used matte paintings (albeit of a fancy, 3D nature) for the skylines on many of the planets you can explore, creating some of the most beautiful alien vistas ever depicted in a game (or on film, for that matter), working past the technical limitations that would have otherwise prevented the rendering of such breath-taking views. Of course, the primary limitation of matte painting is that it only works for distant things; as soon as players are able to actually get close to something, its flat, unrendered nature is revealed.
Silent Hill 2 also embraced its technical limitations to great artistic effect. The environmental fog present throughout the game allowed the limited hardware the game was designed for to render the environment, but the fog served as more than a mere crutch. Instead of being something necessary to accommodate the limitations of the PlayStation 2, the creators embraced the fog and made it part of the prevailing atmosphere, using the unknown as a tool to convey the dread and dismay the story required.
Invisible walls, on the other hand, have never really been used to great artistic effect in a game, and I doubt they ever shall. Invisible walls don’t exist to expand artistic license. Instead, they serve to cut players off from the game world, usually to funnel them down pre-determined paths or to prevent them from seeing the limitations of the rendering engine. The image I started this post off with is one of the most egregious cases of an invisible wall I have ever seen; most are used in far less accessible locations, usually to prevent players from exploiting physics engines to “climb” mountains and bypass content.
I maintain that this is unnecessary.
There is no need for invisible walls. The players who most frequently run across invisible walls are explorers, those who play largely or in part to push the limits of your game and engine and explicitly attempt to access locations meant to be difficult or impossible to enter. Explorers are the most likely to be forgiving of terrain glitches, texture holes, or world breaking. That’s what they’re looking for; the thrill is in doing something unintended, outside the normal flow of play.
Invisible walls break immersion, far more so than would seeing through the back side of a texture would. We all know we’re playing a game; we know their are limitations to what a graphics engine can do. We know short cuts are taken. Players are far more forgiving than we’re given credit for – at least we are until you commit the cardinal sin of restricting our freedom.
One of the central points of games is the interaction – taking part in the world, going where we decide to go, doing what we decide to do. Forcing us down your path is an exercise in futility; we WILL find a way to break your rails. Your work will be far more well received if you work with us on this, rather than fighting us on it. If it LOOKS like we should be able to go somewhere – we should be able to go there.
Some people decry Fallout: New Vegas for their funnelling players down a single path. While it’s true that New Vegas had a dismaying amount of invisible walls preventing you from bypassing certain obstacles, this is rarely mentioned in such criticism (but I’ll mention it: seriously, Obsidian, you’re great and I love you but please never do that again, okay?) Instead what is mentioned is the groups of Cazadors and Deathclaws that “blocked” the obvious path north from your starting place to New Vegas, your (immediate) ultimate goal.
Instead of this being bad, however, I view this as “the right way”. Other games would have simply explicitly blocked your access from that area, or, worse, committed the sin of Oblivion and level-scaled challenges under the guise of “player freedom” to go wherever you wished, thus destroying the game’s verisimilitude. New Vegas put an appropriate barrier in place; you could avoid the high-level obstacle and take the long way around if you weren’t looking for a challenge based on avoiding an obstacle, or you could tackle the obstacle, using stealth, guile or brute force to try to bull through it.
And it’s entirely possible to work around the Deathclaws and reach New Vegas at level 6. I’ve done it. If travel were easy in the Mojave, people wouldn’t need Couriers. Better a meat wall than an invisible wall, I say. Or better yet, no walls at all.