Does Mario Kart’s blue case actually work? An investigation

Mario Kart’s Blue Tank (officially the Spike Tank) is one of the most iconic items in video game history. But it’s also one of the most controversial. A staple of the series since Mario Kart 64, the Blue Tank is a laser-guided projectile that targets the player in first place. It’s almost unavoidable, and even completely unavoidable in older games. Every Mario Kart player knows the feeling of dread – and childish injustice – that accompanies the Blue Tank’s sudden, high-pitched siren wail, heralding an inglorious end to your comfortable racing lead. But a research project at Queen’s University Belfast has posed a fascinating question about the Blue Tank: does it even work?

Of course, the blue shell works in a literal sense – it blows up the hopes and dreams of the first place winner with depressing accuracy. The question is, does it do what it was designed to do and what people think it does? And if not, then why is it such a central part of the game?

The blue shell’s fame can obscure its unusual status in gaming: it’s surprisingly rare for items in competitive multiplayer to specifically target the leader, let alone incapacitate him for several seconds. “Isn’t that (…) a bit unfair?” Kotaku asked Hideki Konno, “the man behind Mario Kart,” skeptically in 2011. One answer would be that it doesn’t have to be fair: “Unfair” game mechanics are very important to the functioning of many games. Overly hard bosses, unpredictable traps, and harsh penalties can help build a world, give a game a sense of risk and difficulty, and shape players’ responsiveness.

But that’s not the answer Konno gave. Instead, Konno explained that the Blue Shell was invented to increase the competitiveness and fairness of racing: “We wanted to create a race where everyone is in it until the end.” Various defenses of the Blue Shell are based on the same idea: that the Blue Shell is “obviously” a mechanism to maintain competitiveness. “Most obviously, it’s the Great Equalizer – the towering blue embodiment of pure carnage that gives players at the back of the pack a fighting chance,” Nathan Grayson argued in 2014, citing a video by popular YouTuber Extra History: “One reason for the Blue Shell’s existence is obviously that it serves as a catch-up mechanism (…) The Blue Shell helps ensure that no one is left completely in the dust without a chance to catch back up.”

But is that true? Does the blue shell help keep races competitive? Alex McMillan, then a computer science masters student at QUB, set out to test this gaming wisdom. They developed a metric called “competitive closeness” to measure how close Mario Kart races are: Essentially, it averages the distance between each consecutive pair of cars – first and second, second and third, etc. – and thus measures how close the race is as a whole, rather than just the race between first and second. (After all, if you beat Pink Yoshi in a bad race and come in fifth, that may be the deciding factor for you, and the blue shell is specifically designed to help those at the back.)

Then it was tested. 50 test participants each completed three races in Mario Kart 64, all on Luigi’s Raceway (to avoid environmental hazards affecting the results). One race had the normal chance of getting a blue shell; one had three times the usual chance of getting a blue shell as long as you were far enough behind to be eligible; and one race had the blue shell removed entirely.

The result? Blue shells don’t have a significant impact on how close Mario Kart races are. They might make the race leader swear loudly enough to scare the cat, but unlike, say, golden mushrooms or bullet bills, it doesn’t really help the player who gets a blue shell. So it’s pretty official: the blue shell is not a fairness or competitive mechanism, and it doesn’t do what it was officially designed to do.

But Kosuke Yabuki, the director of Mario Kart 7 and 8, told Eurogamer in 2017 that when developers experimented with removing the blue shell, they concluded that “something in the game wasn’t quite enough.” Even though the mechanical function of the blue shell is surprisingly small over the course of a race, it does serve an important psychological function for players. What could that be?

In her conclusion, McMillan speculates that the Blue Shell is for players whose goal has changed: they are so far off the pace that they no longer expect to win and may feel disconnected from the race. The Blue Shell gives players farther behind an “illusion of agency” so they “still feel like they can influence the race.” The Blue Shell allows the group of players to feel a sense of excitement and glee that comes with the race leader’s panic, but it also allows the player who threw it to feel noticed, impactful, and dangerous. In a game with a lot of pent-up frustration, the Blue Shell allows stragglers to take out their frustration on the race leader, and this could help the group—or even a solo player—release some pent-up tension and feel more positive about playing.

Yabuki himself hints at this: “I personally place a lot of importance on the human emotions of the gaming experience,” he says, “and if you experience something that seems unfair to you or makes you angry… Everyone is different in that regard. What you perceive as unfair may be something different to someone else.” Yabuki describes wanting to balance the emotions of the experience so that even if a particular player is frustrated on a particular day, they will still return to Mario Kart next week. So the blue shell can help spread the frustration across a larger group rather than concentrating it on specific players.

Items that prioritize speed, especially at the expense of other players, are usually most useful for helping those behind catch up: “Lightning bolts actually do what players expect the blue shell to do, because they slow everyone down except you,” McMillan notes. So if you really want to fight for the win, you’ll want to prioritize speed items. But Mario Kart isn’t just a video game; it’s first and foremost a social game, and the accidental genius of the blue shell comes from that: the blue shell can give less skilled or less lucky players a way to vent without spoiling the mood, and it can remind race leaders to look out for their friends, even if it’s just to give them the middle finger.

So the next time you send someone a blue shell, remember that it is done in the spirit of friendship.