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The psychology of Diablo III loot

Psychologist and Gamasutra contributor Jamie Madigan returns to explore the psychological factors at play in Blizzard's Diablo III, offering insight into why its loot system doesn't feel as satisfying as it should.

Jamie Madigan, Blogger

June 25, 2012

12 Min Read

Oh man, you all, I've been playing a lot of Diablo III lately (click click click click click...). I'm sure that many of you who have played have been through the same scenario I have time after time. After running around avoiding AOE attacks, dashing in to rez fallen teammates, and swatting aside trash mobs, you and your co-players finally deplete some boss's health and immediately gather around the newly created digital corpse to answer that all-important question: Did it drop anything good? In some of the most important ways, Diablo III is a game about hitting monsters with weapons until other, hopefully better, weapons pop out of them. That is, it's a game where you try to maximize the outputs of a system through optimal combinations of your character's skills and equipment. This puts acquiring new gear first and foremost (especially once you hit the level cap of 60 and start running Hell or Inferno difficulties) but unlike previous games in the franchise, Diablo III complicates that process by having auction houses where you can buy and sell equipment so that loot drops aren't the only way to deck yourself out with phat lewts. As is my habit, I've been thinking about how different psychological theories explain our willingness to buy things in the auction house and grind for new equipment from in-game drops. The game's developer, Blizzard, probably has two goals among others: First, to get people to spend their in-game gold to keep the game's economy moving (or real money in the case of the real money auction house), and second to keep us playing the game over and over again in order to find stuff the old fashioned way. In pursuit of these goals and in light of certain psychological phenomena, I have three suggestions for Blizzard or anyone else developing a similar system.

By default, sort the auction house by buyout price, high to low.

Consider these two questions:

Is the height of the tallest redwood more or less than 1,200 feet? What is your best guess about the height of the tallest redwood?

What do you think? These are questions that researchers asked of some visitors to the San Francisco Exploratorium. Other visitors were asked a similar pair of questions, except that the first one asked whether the tallest redwood was more than 180 feet instead of 1,200. Both limits are pretty extreme, in that 180 feet is obviously way too short and 1,200 feet is crazy tall. Nonetheless, the answers to the second question, which was consistent across both groups, were pretty amazing. On average, those who had been primed by the 1,200 feet figure said the tallest tree in the forest had to be 844 feet, while those who heard 180 feet off the bat thought the tallest had to be only 282 feet. These were the same people, looking at the same trees; the only difference was the figure in that first question. This is a clear cut example of what psychologists call "anchoring," one example of which is presenting us with a number to change our estimates of an other, possibly unrelated number. Simply seeing the numbers 1,200 or 180 caused people to anchor on that number and to then adjust their estimates of the tallest tree instead of picking a more sensible starting point. This kind of effect shows up everywhere once you know to look for it. It's the basis of lowball sales pitches that get you to anchor on a low price and then negotiate up. It's the reason why many fast food restaurants list bigger, more expensive drink prices first on their menu. It's why the "But wait! There's more!" brand of infomercials list absurdly high prices for their wares first before slashing them down for a limited time if you act now. And anchors can still have an effect if they're nonsensical or random. Behavioral economist Dan Ariely and his colleagues conducted a study where they used anchoring in an auction simply by having bidders write down the last two digits of their social security number at the top of their bid sheets. Those whose numbers ended in the 80s and above actually were willing to pay up to 346 percent more for things like wine and chocolates than were those whose social security numbers ended in the 20s or below. This is why I think that if Blizzard wants more money spent in the auction houses, one way to effect this is to pre-sort the buyout prices so that we see the big fat numbers first in our search results. Even absurd ones like where that one numbskull obviously just held down the "9" key for 30 seconds. Seeing larger numbers will prime us to inflate our estimates of what that item is worth to us. If Blizzard wanted to get really sly about it, the company could show you the most that an item has sold for over the last 7 days.


Of course, savvy auction house shoppers can use this information to avoid the anchoring effect. Setting price limits in the auction house filters would mitigate it, for example. Me, what I typically do is set some price limits with the filtering tools, then sort by ascending price rather than descending. That way, I anchor on the low prices instead. But what about getting loot the old fashioned way -- by grinding for it? What can Blizzard do to keep us grinding? That brings us to the second suggestion.

Activate the availability heuristic with 'Phat Lewt' notifications

There's a setting in Diablo III that lets you see when someone on your friends list pops achievements. For example, when your buddy beats Diablo (OMG SPOILARZ!!) for the first time on Hell difficulty and earns the associated achievement, you get a little notification near the chat area, along with an icon. It's a neat social system that I think could be expanded to make people keep grinding for super awesome Rare or Legendary item drops. To illustrate why, consider a simple, 1973 experiment by Amos Tversky and Daniel Kahneman where they created a tape recording of 39 names. Nineteen of these names belonged to famous people, and the remaining 20 did not. When asked, 66 percent of the subjects were able to recall more famous names than non-famous, and the vast majority --80 percent -- incorrectly claimed that there were more famous names on the list than non-famous. The reason for that last result, the researchers argued, has to do with what's called the availability heuristic. In short, it refers to the fact that to the degree that recalling instances of an event or class of things from memory is easy, we will judge them to be more frequent or more numerous. In his book, Thinking, Fast and Slow Daniel Kahneman digs even deeper into the phenomenon, arguing that it's an example of how part of our mind (the eponymous "Fast" part) will slyly substitute an easier question (How easy is it to recall an example of this phenomenon?) for a more difficult one (How frequent is this phenomenon?). There are many factors that make an event or thing easier to remember. For example, it may have happened in a very dramatic manner, it may have just happened recently, it may have affected you personally. The availability heuristic is the reason people thought school shootings were more common right after the 1999 massacre in Columbine, Colorado. It's the reason most people overestimate the divorce rate in highly visible Hollywood couples. It's why you think the Xbox 360 "red ring of death" failure is more frequent after it happens to you.


This is why I think that the achievement notification in Diablo III is a good start. It makes the number of people getting the achievement seem larger because it happened recently and to someone you know. The same effect could be used to make players think that the upper tier of Legendary item drops are more frequent if they saw a notification every time it happened to a friend. This would motivate players to keep playing in the (perhaps inflated) hopes of getting a similar drop. Blizzard could also post similar notifications about crafting high-end gems or blacksmith items. Or cracking the 10,000 DPS threshold for the first time. Seeing notification of these events will make them seem more frequent and thus more likely to happen to you if you just keep at it. So far we've talked about the auction house and about getting loot drops from playing the game. Thinking about the interaction between the two brings us to the final suggestion.

Create dopamine rushes with bind on pickup items

Instead of Tristram, let's head to Sweden to begin. Wolfram Schultz was working there as a neuropsychologist studying Parkinson's disease in lab monkeys when he almost accidentally started a line of research that ultimately suggests a way that Blizzard could encourage us to keep grinding for new loot. Schultz's research involved dopamine and dopamine receptors in the brain. Dopamine is a chemical that's released when we encounter something pleasurable, like a piece of fruit or a Legendary Mighty Weapon for our Barbarian. The chemical is hugely important for learned behavior and motivation to persist in a task, since when it's released certain brain cells go bananas and make us feel good -- maybe even euphoric. What this means is that dopamine receptors are part of a system that's about pattern recognition and figuring out how to get more good things out of life. Schultz and his colleagues discovered that presenting a lab monkey with a bit of fruit caused the creature's dopamine neurons to light up. They also discovered that when they repeatedly preceded the treat with a light or a sound, the neurons would start to fire when the monkey saw the light or heard the sound, but then remain relatively inactive when the fruit showed up. The system they had discovered was, at its core, about anticipation and trying to predict rewards based on what was happening in the environment. What's more, it turns out that unpredicted gushes of dopamine really get us fired up. This is because unexpected dopamine rushes highlight failures in our predictive system, and it's a system that's designed to help us figure out why we didn't see life's good things coming and thus how to find them again in the future. This is why the random nature of loot drops in many games is so effective at getting us to keep playing: it capitalizes on our brain's attempts to predict the unpredictable. (See here for more on dopamine and loot drops.) Loot drops were indisputably core to the Diablo and Diablo II experience for all these reasons. Hearing the little "ting!" sound and seeing the beautiful, colored text indicating that a unique item had dropped produced a rush that every player looked forward to.

Only, not so much with Diablo III. The reason is that the auction house is actually a far more effective but much more predictable way of finding better gear for your character than hoping for good loot drops from fallen enemies or treasure chests. In my experience it was super easy to buy equipment so good that the magical "ting!" sound soon lost its effect because the loot that dropped was no longer a reward. It was just gold in a slightly more inconvenient form, destined to be sold to a vendor or at best on the auction house for a little more. In effect, the auction house system excised the entire dopamine rush, loot drop appeal of the game. Yes, high quality items still mean big returns on the auction house, but the whole process of listing, selling, and transferring the money is too far removed to elicit the same dopamine rush. I suspect that the execs from Blizzard are too busy cackling and having money fights with the cuts that the company takes from real money auction house transactions to care, but this seems like a huge part of the game's core appeal is now lost. I think there's some middle ground, though, which is why I think the game should have a class of super items that are bind on equip. In MMO parlance, "bind on pickup" or "BoP" items are treasures that bind to your character's account once they're equipped. This means they can't be given away, sold, or otherwise transferred. You can just equip them, break them down for crafting materials, or just sit there and stare at them in your inventory. Finding a really good, color-coded item that's BoP would restore some of that "ting!" feeling and dopamine rush, because it will be something that you won't be able find on the auction house. Making the best items in the game BoP would go a long way towards creating those familiar dopamine rushes because they would signal a clear and strong reward, but even making them run the full range of quality would probably still work, since seeing one drop would signal the tantalizing possibility of something otherwise unobtainable. Suddenly, the loot drop would be back, baby. So there you have it: three suggestions for tweaking Diablo III loot based on psychology. If you're a game designer I'd love to hear your thoughts on these, especially if you've experimented with anything similar.

Dr. Jamie Madigan is a psychologist and a gamer who writes about the intersection of those two topics at Psychologyofgames.com. He is also a level 54 wizard.] Citations Ariely, D., Loewenstein, G., & Prelec, D. (2003). Coherent arbitrariness: Stable demand curves without stable preferences. Quarterly Journal of Economics, 118, 73-105. Jacowitz, K. and Kahneman, D. (1995). Measures of Anchoring in Estimation Tasks. Personality and Social Psychology Bulletin, 21, 1038-1052. Kahneman, D. (2011). Thinking, Fast and Slow New York: New York. Tversky, A. and Kahneman, D. (1973). Availability: A heuristic for judging frequency and probability. Cognitive Psychology 5, 207-232.

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