Most commonly, the term “Invisible Wall” is referred to in video games and they are most frequently noticed when their presence just does not make any sense. For instance, imagine a chest-high barrier, which player-controlled character should undoubtedly be able scale over, only to smash his face into an invisible barrier, which extends from the static mesh all the way to the sky. While it may sound like a hypothetical example, there is an excess of games, which are plagued with horrendous invisible wall placements.
Cases of bad invisible wall implementations
Fallout 3 comes to mind as one of the most notorious offenders in bad invisible walls placement I have seen in recent time. Despite the fact that players are given a large open world to explore, whenever a virtual boundary of the world is reached, players are stopped in their tracks by an invisible barrier accompanied by a message, which tells them to turn around and proceed the other way. What makes the matters worse, is that it is difficult to tell where the world boundaries are without looking at the map, since most these virtual boundaries are not walled off by any natural formations, like mountains for example. Quite the contrary – most of these boundaries look like an extension to the game world, featuring large open areas with appealing backdrops, deceivingly placed there just to fool the player.
Another open world game with bizarre invisible wall mechanics is Far Cry 2 released in 2008. If the protagonist wanders off too far into the African desert, the game forcibly passes him out followed by a rough transition back to the walled off garden that is the game world. No explanation throughout the game entire game is given on why the protagonist cannot leave the map boundaries. Players themselves would have to figure out why the character falls ill when the boundary is reached, and why he is magically placed back into the playable zone moments after.
There are several other cases when bizarre placement of invisible barriers and collision boxes can create a baffling experience in the game. For instance, early Medal of Honor games released for the original PlayStation console had strange instances when an enemy could not by killed if he stood behind a chain link fence, even though the gaps themselves were large enough to let a bullet through. In addition, shooting an enemy through a seam between the stairs was also impossible, thanks to invisible barriers placed in the seams.
Proper implementations of invisible walls
Previously mentioned examples displayed improper implementation of invisible walls, but are there any games, which feature unobtrusive invisible wall, thus justifying the word “invisible” in this term? First game, which springs to mind, is Borderlands. The implementation of invisible boundaries in its open world sandbox was excellent. Instead of having players face an invisible barrier, which stops them in their tracks, unmanned turret guns would be deployed where the world boundary exists. If players were to wander off past the boundary, they would be warned with an audible message. However, if they failed to comply, and still kept on venturing forward, those auto turrets would blast them to pieces for disobeying the warning.
Battlefield games also have a pretty effective and unobtrusive implementation of level boundaries. Since most of the levels take place on an open terrain, it is granted that the player would eventually leave the playable space. However, the game dealt with such issue in a similar fashion as Borderlands: if the player were to wander off past the boundaries of the game world, the game would warn them that the player-controlled character would be shot for deserting the battle. In the context of the game, this makes perfect sense, providing that in the real world scenario, similar punishment is carried out to deserters.
Speaking of a different approach to limiting player progress, Diablo 2 had a few novel ideas, which are hard to come by even in contemporary games. The game world was open to the player, though if the game detected that player-controlled character’s level was not high enough as he was to venture in a new area, a patrolling guard would stop the player warning him that enemies, which dwell ahead are too powerful. From that point, it was fully up to the player whether he wanted to turn back or venture ahead disregarding the warning. In many cases, the latter option would result in swift death, but that is all right, since the game warned the player about the dangers ahead and his/her disobedience was punished.
Conclusion
In the end, invisible walls are here to stay, as they are vital elements in level design. Thanks to them, navigation around complex geometry can be made more fluid, players can be kept out of unreachable spots and object collision can be made possible. Unfortunately, it is the improper deployment of invisible barriers is what gives them a bad name. It is entirely up to level and game designers to ensure that they limit player’s progress and approximate collisions in an unobtrusive way. In addition, as we could see from examples provided before, all that is needed is a little bit of wit and creativity.
Note: an edited version of this article was originally published in PlusFiveInt
