Call of Duty 4: Modern Warfare is a tremendously popular first person shooter -- fast-paced and nerve-wracking. Being good at it required great reflexes, fantastic hand-eye-coordination, and a fair deal of strategic thinking. Being good at Call of Duty is hard, and not everyone can be competitive on the leaderboard...At least, that was the intent. The map Crossfire in Modern Warfare illustrates beautifully how a detrimental meme can gain a foothold because of the game's internal rules.
The Crossfire map was very popular because it supported a range of different play styles, but there was a crucial design element of the map that gave rise to some of the most frustrating and prevalent behaviors in Modern Warfare. The opposing teams would start on either end of the map, separated by various buildings and other obstacles. To get to the enemy, you would have to leave the relative safety of your starting location and move into the more dangerous warzones in the middle of the map. To be a successful player on the Crossfire map, you had to strike a difficult balance between forward momentum and tactical retreats -- it was a difficult map with a lot of room for improvisation. Topping the leaderboards on the Crossfire map could prove very difficult.
But players quickly found a way to get cheap points. One of the walls that separated the two teams early in the game was low enough for a grenade to be blindly thrown to the other side. There was a good statistical likelihood that an enemy would be on the other side, and chance would determine if you got a "free" point or not. The combination of predetermined starting points and insufficient obstacles between the teams had allowed one creative player to get a stylish kill.
The very first time it happened it was undoubtedly impressive -- to have invented the technique, you needed to have a very intimate knowledge of the game and the map. The problem was that the meme was easy to copy, without requiring any particular skill at all.
More and more people started blindly throwing grenades over that wall, which decreased the chances of each individual thrower getting a point -- but increased the chances of a hapless opponent being unfairly killed early on. The "nade spamming" meme was the perfect storm of unfortunate circumstances.
The strategy was attractive to players because it was easy to use. Very little skill or exertion was needed to have a chance at a free point or two, so a lot of people gravitated towards it. The cost of trying it was also exceedingly low -- in the fast-paced environment of the Crossfire map, it would be hard to use the grenades later on, so you might as well throw a few off early in the game and hope for the best.
And in hoping for the best lay the second rub. Random interval reward schedules can be incredibly addictive. The fact that you didn't know if you would hit an enemy or not turned throwing the grenade into highly addictive gambling scenario. All you had to wager was a cheap grenade, and you could win very desirable points in exchange. It was a meme that was easy to copy because it was so easy to observe and understand the required actions, it was fairly successful at a low cost, and it was very addictive.
The more people copied the meme, the faster it spread, and after a while the meme was so prevalent that it was expected behavior. Both teams would throw grenades over the wall in the first 20 seconds of the game, and chance would determine how many players from either side would be taken out of combat before the battle even begun. Needless to say, being taken out in the first 20 seconds of the game is incredibly frustrating -- but if you chose to avoid the situation where you could get killed early, you would forfeit an opportunity to stay competitive with your teammates.
Once the meme had become popular enough, no one really stood to gain anything from it anymore. Too many people were nade spamming, and the overall fun of the game was taking a severe hit. The problem was that the meme proved very difficult to eradicate -- the cost of changing the map itself was prohibitive, and for game hosts to kick offenders proved to be a task of Sisyphean dimensions. The viral meme was spreading too fast to be contained. The internal rules of the game made it fantastically easy for the meme to spread; KillCams would replay the moments before your avatar's death, and the victims quickly caught on and reciprocated with more nade spamming. Teammates on either side observed the behavior and joined in.
Although the behavior had been perfectly rational, beneficial, and entertaining before the meme become widely adopted, the situation changed with scale. There was only room for so many people to nade spam, but there was no mechanism from preventing everyone from having a go at it.
In game theory, what happened to Modern Warfare is referred to as the Tragedy of the Commons, and it is a surprisingly common occurrence in all kinds of everyday situations. But the problem of containing the spread, and preventing the Tragedy of the Commons, is better explained with another game theory classic: the Prisoner's Dilemma.
Because the meme was so easily copied, players would have to reach an agreement (explicit or otherwise) to cooperate in maintaining its spread. If everyone agrees not to nade spam, the game will be more enjoyable for everyone. The problem is that once people have stopped nade spamming, the winning potential for someone trying it gets very high -- and it only takes one defector to nudge the uroboric cycle back towards the Tragedy of the Commons. Richard Dawkins, the father of meme theory, explains the phenomena of both the Tragedy of the Commons and the Prisoner's Dilemma very well in his 1987 documentary Nice Guys Finish First.
Interesting to note is that the KillCam was designed as a way of deterring people from engaging in negative behaviors like nade spamming and spawn camping. Although the KillCam introduced an element of penalizing the bad behaviors, it also created a new and very effective vector for the memes to spread. Measures like the KillCam are double-edged swords: on one hand, they punish wrongdoers, but recruit more wrongdoers on the other. At the end of the day, Modern Warfare's internal rules gave birth to an optimal winning strategy that was not in line with the desired behavior of players.
Designers should take great care when creating the internal rules of their products, as the in-game culture that the game will inevitably have can have a greater impact on the product than your own direct design input. The meme can be a very powerful friend or foe, and although the meme cannot be tamed, we are ultimately the architects of the environments in which they spawn.