Could Markov chains be applied to any other data sets for hilarious effect? By using Slatton’s Python implementation of Markov chains plus 300,000 descriptions of public GitHub repositories retrieved from their API, I discovered that statistical randomness can indeed create funny innovation.

You can download a list of 1,000 Markov chain-generated projects here. Here are a few interesting ones:

• MaNGOS is a free, Open Source implementation of a tag at relatively random intervals.
• A Warhammer 40k simulator to teach myself both OpenGL and Clojure
• Perl interface to Git repositories via Ruby.
• A windows live messenger network client written in Erlang
• Rails plugin which allows to talk anonymously and use tripcodes if you want.
• A Firebug extension for displaying the latest from Hacker News
• Sinatra-inspired JavaScript node.js web development framework for lua. Inspired by rspec
• Inverted Index on top of Tornado
• Android LED interface library for various wave propagation techniques.
• CatchAPI is a Java API to remove the need for boring project setup.
• Adds basic social networking capabilities to your lighting system based on the concept of the Working with Rails
• Brute force your OpenERP data integration with flatfiles
• Culerity integrates Cucumber and Celerity in order to shutdown the computer.
• Parses ANSI color codes and converts them to iphone compatible mp4s using HandBrake
• A simple OFX (Open Financial Exchange) parser built on top of WordPress. Rolopress core theme

The code used to get the project descriptions from the GitHub API is available in this GitHub repository, and you can download the ~300k repo descriptions here. [5MB .zip]

Obviously, developers would prefer that their users not uninstall the software that they spent years creating. Regardless, developers should ensure that the uninstall process works properly.

Otherwise, a poorly coded PC game uninstaller could delete not just the game, but the entire hard drive. That would be a problem.

Ragnarok

In late 1998, Bungie (which would later create the Halo series) released Myth II: Soulblighter for Windows. Myth II, a real-time tactics game, was received with great reception and highly-positive reviews.

But before the worldwide release, a Bungie employee uninstalled version 1.0 of Myth II, and afterwards, her PC refused to reboot:

It was discovered by a very nice young lady in a Japanese office as she worked on the Asian versions of Myth – just as she was trying out the final build. She attempted to uninstall it from the main root folder of her hard drive – not brilliant, but pretty common practice – and perfectly fine for most games. The game proceeded to eat her hard drive like a fresh Bento Box.

The Myth II Uninstaller worked by deleting the folder which contained the game files. However, this implementation assumed that the user installed Myth II in the default directory. (i.e. C:\Program Files\Myth II). If the user installed Myth II in a different directory, such as the system root C:\, then when the user uninstalled the game, all the files in the C drive were deleted. Boom.

As Bungie later explained in a press release:

In certain unusual cases, using the Uninstaller can cause problems. If a user chooses an installation directory other than the default directory, they should NOT use the Uninstaller but should manually drag the Myth II folder into the Recycle bin and delete it.

Anyone who has the game but has not yet installed it is asked to wait for a new version of the Installer which we will release shortly. If you have already installed the game, there is no harm in playing it, but players should be careful not to use the Uninstall executable. If you have already Uninstalled and not experienced obvious problems, there is nothing to worry about.

Calling the potential obliteration of an operating system a “problem” is an understatement.

Although the issue was not widespread, Bungie decided to do a recall of all Myth II CDs and redistribute a version 1.1, eliminating most of the game’s profits in the process.

You could say that the Myth II version 1.0 uninstaller worked exactly as intended: it did indeed uninstall the game. It just worked too well.

UPDATE October 2014: A year after this article was posted, someone submitted this article to the Reddit subreddit todayilearned, where it subsequently went viral. In the comments, Reddit user rdmartell, a former developer at Bungie, posted more insight into the glitch:

So I wrote the Myth TFL installer (not this one). The reason this happened is because you could install other maps and whatnot, and to make the uninstall clean, we had to recursively delete your data folder. In the sequel, somehow that code (which did sanity checks) was used to delete the applications directory, instead of just the data directory in the applications directory. So if you installed it on C:/, it would delete everything recursively from there. Nowadays, uninstall usually leaves any user installed files (like saves or downloaded content) but at the time, as the article suggests, hard drive space was more precious. Also, I wasn’t there for this issue, so I don’t know the above for sure, but having written the previous installer, I’m pretty confident that’s what happened.

Later in the thread:

I actually think the bug was only there if you installed directly to root; not even in a folder. As I recall, that was the only way it deleted your entire HDD. Unless it was discovered later by going into the uninstalled code that it could happen in other cases (which I never heard about), I think the issue was a bit overblown by the media. Still, the last thing you want to be responsible for is nuking a customer’s hard drive.

Small world.

In Golden Sun, you play as a group of teenage mages called Adepts, who wield the power of the four elements (Earth, Fire, Wind, and Water) by casting spells with Psynergy. The antagonists of the game are a pair of jerks who are attempting to reawaken a dangerous and sealed power, and only four kids can stop them from destroying the world. Released two years later, Golden Sun: The Lost Age takes place immediately after the conclusion of the first game with a different quartet of Adepts and a new pair of jerks. In this sequel, it is revealed that the jerks who keep trying to kill you are not the bad guys and the whole conflict is just one big misunderstanding! Yes, the plot is very reminiscent of other Japanese-developed RPGs such as Final Fantasy and Chrono Trigger, but it’s still impressive for a game I typically played in the backseat of a car.

Like Final Fantasy and Chrono Trigger, Golden Sun has an inventory system where players earn new weapons and items by purchasing them at a store or by finding them as loot from defeating enemies in the world. The most powerful weapons, naturally, only drop from enemies at the end of the game with odds of less than 0.01% per kill. If you killed such enemies 100 times, for example, you would only have a 32% expected chance of seeing a rare drop among all the kills. And killing that many enemies could take hours. It depends on the almighty will of Golden Sun’s Random Number Generator.

As it turns out, the Golden Sun RNG is so poorly implemented that players have found out how to make events with 1/256 probability occur one hundred percent of the time.

You Make Your Own Luck

Soon after the first Golden Sun was released, players discovered that the first random enemy encounter the player enters after turning the GBA on was always a First Strike, where the player’s party gets a free turn. Was this a cute gameplay mechanic intended to give the player a quick advantage, or was it indicative of a flaw in the game’s RNG?

Most modern RNGs are partially seeded and randomized using a timer, i.e. the current time of the computer in microseconds. This makes it infeasable to reproduce the output of the RNG reliably.

However, the GBA does not have an internal clock, so time-based methods of seeding aren’t possible. By the time the sequel was released in 2003, the entire Golden Sun RNG was reverse-engineered:

Golden Sun uses the ANSI-C standard rand function as its Pseudo-Random Number Generator.

There is one difference: Golden Sun’s RNG uses an unsigned 4-byte number and returns it with no shifting, so you’d replace “return ((next »16) & 32757);” with “return (next & 4294967295);”

This, ordinarily, is a perfectly capable RNG, but there is one flaw with what Golden Sun does with it.

It only makes a new random number when something random happens. What’s more, it uses two copies of the RNG to create two random numbers, and the first RNG only handles battle situations.

As such, it is easy to control when a new random number is generated.

On top of this, the RNGs are seeded with 0 when the GBA is reset, and because of the way the game has been programmed, the RNG controlling battle events will continue to be 0 even when you load the game…

Golden Sun’s Random Number Generator isn’t “random” at all. It’s manipulated entirely from player-controlled actions, from the moment the Game Boy Advance is turned on.

Get Lucky

One of Golden Sun’s contributions to the typical RPG character class customization is the Djinn system. In the game lore, Djinn are impish creatures that grant enhanced powers to Adepts. There are four types of Djinn, one for each element, that can be found in the overworld, and each Djinni can be used to either increase a character’s statistics, or Unleashed to provide a powerful spell effect. Also, as with many other RPGs, Golden Sun implements an elemental rock-paper-scissors combat system: enemies are weak to an element and resistant to another.

A GameFAQs forum user by the name of “darkpanther” discovered that using a Djinn Unleash with an element that is the enemy’s weakness will not only increase the amount of Experience and Coins earned, but also quadruple the chance of the enemy dropping a rare item. (this fact is neither hinted anywhere in the game nor stated in any strategy guides)

This is essential toward manipulating the RNG. Normally, the rarest items such as Tisiphone Edge and Lachesis’ Rule have an “Item-Class Chance” of 9, meaning the item has a 1/(2^9-1) = 1/256 chance of dropping per enemy kill. The “DP Method” decreases the ICC by 2, meaning the new drop rate becomes 1/(2^7-1) = 1/64. But:

As ‘unpredictable’ as RNGs seem to be, if they are always seeded to the same value and do not use a timer-based response, they will become predictable by anyone who is good at noticing patterns. One pattern being, for example, that the 31st random number that is calculated - 33727075 - will drop any item if the enemy dying when this random number was called was just killed by an elemental Djinn attack that it is weak to.

Calculating the 31st random number would fail against an ICC9 item, but now works against an ICC7 item. (and all items of lower ICC too)

Therefore, in order to guarantee that an item drops, kill the appropriate enemy with an element-advantage Djinni such that the 30th random number is generated. (the 31st random number is generated on the enemy’s death)

How do you ensure that you only create 31 random numbers? From the Golden Sun Wikia:

Save the game and do a hard reset in the area where the monster that drops the item you need appears. Run around to get in a battle. If the encounter consists of a formation of 2 monsters, with at least one of them being the monster you want, proceed. If not, do another hard reset and try again.

During battle, have the entire party use multi-targetting Psynergy on the targets in the first turn, and since a battle right after a hard reset always involve your party attacking first where possible, the monsters will not be able to act. During the second turn, use two multi-targetting Psynergy on the enemies, and have the third party member (or fourth, if one of the three party members that act before uses Defend) unleash an attack Djinni of the element the monster is weak to on the monster. If by this point, the monster flashes in colour and dies, you will obtain the drop of that monster at the end of the battle, however rare it is. If the monster does not die then (either dies too soon or doesn’t die by this step), adjust the power of your attacks until you get it just right.

Moral of story: if you’re making a video game, seed your RNGs with an algorithm that players can’t manipulate 100%. Otherwise, hilarity will inevitably ensue. I forgive Camelot for implementing a simplistic RNG though; the two games’ awesome soundtrack more than makes up for it.

You play as Samus Aran, an armored bounty hunter who has infiltrated the base of the dreaded Space Pirates on Planet Zebes. Samus must defeat the leaders of the Space Pirates: the dinosaur Kraid, the dragon and memetic badass of the series Ridley, and the AI construct Mother Brain. Additionally, Samus must find a way to defeat the Metroids, which are nearly-indestructible parasites that threaten all life. Yes, this was a plot written in the 80’s.

Since the NES Metroid cartridge did not have the ability to save games, and the game itself took awhile to complete, Nintendo developed a password system to allow players to continue at a later time. Upon death, the player received a 24-character alphanumeric password that could be entered to restore all items the player has unlocked and remember which bosses the player has defeated. Most of these passwords were gibberish that required a pen-and-paper to write down and remember.

One password, however, is more memorable, and much more sinister.

The Password is Always Swordfish

Even before the days of the internet and personal computing, players found passwords with unique properties.

The Narpas Sword password:

is essentially the debug mode for the game, with all items unlocked, infinite health, and infinite health for Samus.

Another, more revealing password is the Justin Bailey password:

This password starts the game with most unlockables obtained, but more notably, it changes Samus’s sprite from an armored powersuit to a bikini swimsuit.

One password, discovered over 20 years later, long after the Metroid password system had been completely reverse-engineered, does not grant you all items. This password just crashes and resets the game:

WTF?

On a NES and various other rereleases, inputting that code will cause the game to either simply reset or transform the game into a glitched wonderland:

But what happens when you enter the password on an emulated Virtual Console, where the game environment is sandboxed? In the case of the 3DS Virtual Console, the 3DS completely crashes:

Rated E for Everyone?

You may be asking “did someone at Nintendo actually program a consequence for profanity in the game? Is the glitching and crashing a punishment for the perverse player?” In truth, the password is merely a coincidence.

As mentioned earlier, the password algorithm for Metroid has been reverse-engineered, and you can actually download a program to both generate and interpret such passwords here.

The profane password is indeed a legitimate password (in which Ridley is already defeated, ironically enough). But why does it crash the game? The Metroid Password Format Guide explains the secret:

There are five valid start locations. They are specified using bits 64-66. To start in Brinstar, all the bits should be off. Norfair, Kraid’s Lair, and Ridley’s Lair can be specified by turning their bit on and leaving the others off. Tourian is specified by turning on Norfair and Kraid’s Lair simultaneously. Any other combination of these three bits is invalid and will cause Metroid to reset.

The reset bit is part of the start location. There are 16 possible values, but only 5 valid ones. Turning on the reset bit will produce and invalid start location and cause Metroid to reset. This is why it is called it is called the reset bit, because it guarantees an invalid password.

For the profane password, the reset bit is turned on, so it will always cause a reset. And that’s why the weird behavior happens.

If you manually disable the reset bit using this tool in order to make the password valid, the new password becomes:

Not as catchy, unfortunately.

In fact, the Justin Bailey password is also a completely coincidental password. Sometimes, passwords can just do very unexpected things.