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March 31, 2009



Speaking of car CD players: I think my 2002 Grand Prix GT is either non-random or the firmware developers programmed a joke into it. One day it played my Nine Inch Nails - Year Zero tracks in the following order: 1, 3, 5, 9, 11, 13, 15, 2, 4, 6, 8, 10, 12, 14, 16. I bought a lottery ticket that day, just in case but did not win.


Well, blizzard got lots of bug reports on their RNG initially because it was, in fact, buggy. During the initial release, it wasn't uncommon for guilds to do entire Molten Core runs getting almost exactly the same drops as the week after week, sometimes exactly the same drops for an entire run. And when you have 10 bosses with giving 2 of 8 drops each on an approximately even distribution, the odds of that happening are vanishingly small. They 'fixed' this by moving to token drops instead of individual class drops. Yes, people don't recognize real randomness. But there was a problem.


I hear Civilization IV has a karma system. Basically, you get a bit of karma every time you fail in a battle proportional to how unlikely to fail that battle (so you get more karma to fail if you had 90% chances of winning than if you had 10% chances of winning). That karma then increases your chances of success for the next attacks.

Another approach is how in Settlers of Catan (on XBLA anyway) you can play with a set of cards instead of dice. The cards have the same proportion of each number as a "normal" spread of dice rolls. Instead a rolling the dice, you just pick a card and remove it from the stack. Once you're down to 3 cards, the deck is shuffled again. The nice thing is that limits the amount of lucky or unlucky streaks you can get. The bad thing is, it reduces randomness: if you drew a bunch of sevens, then you know that fewer sevens are coming in the future and plan accordingly.

Nathan McKenzie

I've slowly been coming to the conclusion that this topic is one of the hallmarks of the truly good game programmers I've worked with, compared to most other programmers - they have, I guess, an aesthetic relationship to math, statistics, interactions, correlations, shaping of possibility spaces, and so on - the ability to use equations and algorithms to produce results that are "good" rather than just "right" (which often means using math the way an impressionist painter might use paint rather than the way a physics professor uses math).

In the case of probabilities specifically, I wonder how much can be traced to D&D - a lot of times it seems game makers default to rules that involve purely random chance that has no memory and no connection to any other values that have been produced (of course you have a strength of 17 and a constitution of 5! The dice said so!). Makes good sense when fallible humans are running a game (and where Dungeon Masters routinely organically do, in fact, fudge random results that are aesthetically unfortunate), but clearly there's no reason that ought to be the default for computers which, really, a pretty fond of remembering numbers and doing math.

Max Szlagor

I can't count the number of times I have had this conversation with programmers on several different projects. Often times, I'll bring up the point that true randomness is not fun because of scenarios where items drop irregularly or enemies reuse the same attacks over and over. The diligent programmer will proceed to check the number generating algorithms and point out that the generator works as intended. The thing is, players don't care about "as intended/accurate" representations as much as they care about fun. Now when I suggest adding a mechanic that requires randomness, I will usually propose a way to weight the randomness in ways that create better player outcomes. I agree with you that doing things this way can be challenging at times and I applaud Blizzard for building this design into their systems and following through with it.

Matchmaking is a whole different ball of wax, and I wholeheartedly agree that ELO/TrueSkill matchmaking kills my enjoyment of online gaming in many cases. The anecdote I always like to bring up is the fact that I had a 0-5 record (approximately) on Ridge Racer 6 for the 360. I'm going to assume they use TrueSkill matchmaking for the time being (which I realize may be a bad assumption). The next opponent I was matched up with was the number 1 player in the world. While I chalk that up to what was probably a low player population count, it was a fairly telling moment for me. The problem is that a good matchmaking system is not enough. I'm a big fan of online systems that allow players to earn rewards along the way whether they are dominating the competition or not(leveling up in Lost Planet, earning new gear/classes in Call of Duty, and earning new ranks and medals in Halo). While this doesn't necessarily fix the matchmaking issue, it keeps players engaged enough to keep coming back. Through repeated practice they can improve their skill over time and gather a new set of tools that can help them win in the future.

On a cheap vacation

I wasn't hoping to find better information on this.

Thank you for sharing your thoughts

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Jamie's Bragging Rights

  • Spider-Man 2
    The best superhero games of all time Game Informer
    Top five games of all time Yahtzee Croshaw
    Top five superhero games of all time MSNBC
    Top 100 PS2 games of all time Official Playstation 2 Magazine
    1001 Games You Must Play Before You Die Nomination for Excellence in Gameplay Engineering Academy of Interactive Arts & Sciences
  • Schizoid
    Penny Arcade PAX 10 Award
    Nominated for XBLA Best Original Game
    Nominated for XBLA Best Co-Op Game