Random Thoughts

2008 February 11
by Vanir

Every now and then I hear an argument that has been around as long as there have been laptops and PDA’s to bring to the D&D table: “You’re not using REAL DICE!”

Some say it takes away from the spirit of the game or sucks the magic out. I’ve seen go so far as to accuse the guy running a dieroller program of cheating. I have to say, I don’t really get either of those.

In Which Vanir Divulges The OTHER Reason He Is Surprised He Successfully Wed

I’m a computer programmer by trade, and I’ve been coding since I was literally about 5. Granted, the programs back then were about the Dukes of Hazzard and didn’t really do much aside from:


20 GOTO 10

Regardless, once I got a little older and learned about generating random numbers, it wasn’t really a giant mental leap when I realized rolling dice was just random number generation for luddites. And while I can say there is a definite thrill in rolling a d20 during a critical moment and having everyone watch the die roll from your hand, hearts leaping in anticipation with every bounce to see if they all live or die — well, that anticipation is still there if the player clicks “ROLL” in his die roller. It does suck a little that everyone can’t see what you rolled, but then again I know lots of people who use DM screens or simply just have too much junk on the table for people to see what got rolled. And I can’t honestly say I haven’t still cheered when one of our laptop-die-rollers saves the day.

“But”, you say, “dierollers aren’t TRULY RANDOM!” Well, no. But it’s close enough. Computers usually use what’s called pseudorandom numbers, which in a nutshell means the computer takes some number it has access to that is going to change rapidly and often (like the computer’s internal clock) and does some math on it that produces a number that is, for most intents and purposes, random. If you’re going to run quantum physics experiments, or you’re a hardcore computer scientist, or you’re just THAT ANAL, then yeah, pseudorandom numbers might not work for you. Rolling d20 to hit a goblin? Not really an issue so much!

Dirty Rotten Cheaters

As far as cheating, anybody who thinks dice are 100% fair is kidding themselves. Loaded dice have been around ever since it became profitable to cheat, and they even sell loaded polyhedrals at Gen Con. And I can remember attempting to come up with harebrained schemes at a teenager with a friend of mine on how to influence our die rolls by spinning the dice or palming a certain number up. It didn’t always work, but it did sometimes. I’d be willing to bet holding the dice funny would get you really closely watched at a casino at the very least!

Sure, writing a computer program that cooked the results wouldn’t be very hard. And I suppose it might be a little harder to detect if cheating had occurred. But if you’re rolling 19 or 20 every other roll, people are going to look at you funny no matter what you’re using.

Besides, people who cheat at D&D need to die from blunt force cranial trauma from a PHB regardless of method.

Die Roller Resources

For those of you who want to use a die roller on your PC or Mac, here’s a good one that probably does WAAAAAY more than you need it to.


Linux guys, sorry — they don’t have a version of that out for you. But if you install Ruby, you can use this instead! (Or write your own, I know how you guys are.)


There’s a swell web-based die roller at Pen, Paper, Pixel:


If you have an iPhone, you could always try out this web-based iPhone dice roller (but don’t tell Yax — he didn’t much care for it!)


Me, I stick to real dice most of the time but if I’m playing somewhere without a real table to roll on I’m using a homebrew application on my Nintendo DS (you’ll need a cartridge that lets you run homebrew).


No matter what you use, it’s always a good idea to check in with your DM to make sure using your shiny new die roller is kosher. PHB’s don’t do subdual!

4 Responses leave one →
  1. Dave The Game permalink
    February 12, 2008

    I’ve had DMs freak out when I’ve tried to use my PDA at the game table when I’ve forgotten my dice. It’s silly to think that dice are any more random. Not just for the loaded dice reason, but because dice theory is this whole other weird field. Most dice are not created well enough to give statistically random results. And even if they are, things like how far they roll and what surface you roll them on to will affect it.

    I roll dice because they are more FUN, but I have no delusion that they are somehow less cheating or something.

  2. ben.c permalink
    February 12, 2008

    “Subdual”? What is this, 3.0? It’s non-lethal damage! 😉

    That having been said, at my table, only physical die rolls count. As a fellow computer programmer, I’m not worried about the randomness of die rolling programs, and while I’ve played with people who cheat before (who would cheat at D&D? I really just don’t understand!), that’s not my present concern.

    We just always have plenty of room to roll and plenty of dice to share around, and physically rolling the dice is an important part of the game for me and the other players at the table. It’s more fun because rolling a die (especially one with more than six sides) has suspense built in, since it usually takes a moment for them to stop and land on a number. On top of that, the suspense is communal, since everyone’s sitting around the table waiting for that 20 (hopefully) to come up.

    It’s not a major issue, but without any significant reason to prefer computer aids, I’d much prefer the physical dice.

  3. mrboffo permalink
    February 13, 2008

    20 GOTO 10″


    I do have one cheater at my table. I’ve taken to having everyone roll dice into the middle of the table. It’s a bit of a pain, but the guy’s a good friend, and cheating on die rolls is pretty much his only fault, in terms of D&D.

    I discovered his strategy during a one-shot game run by a mutual friend. Here’s his system (translated to BASIC, at least as best as I can remember):

    10 LET X=rnd*20
    20 IF X<10 LET Y=X+10
    30 IF X>10 LET Y=18
    50 END

    One of my good friends is a Mathematics professor, and we’ve had a number of conversations about random numbers, and about how no computer program (or die) can generate a truly random number, but that both dice and computers come close enough for our purposes.

    Now THAT’s a geek.

  4. kanati permalink
    March 1, 2008

    There are many ways to improve the randomness of a computer including consistency across platforms such as using the Mersenne Twist algorithm. This is widely regarded as one of the best out there. I know this as I have actually written such a random number generating beast.

    A computer is going to be far more random than dice due to what “dave” said. Dice aren’t machined to be perfectly symmetrical, or perfectly weighted so the theory that one d20 is better than another may actually be true.

    Some people that have created die rollers for computer use actually have at least one of the calculations wrong however in a few cases that I’ve checked. Percentile dice are not 1d100. To replicate the percentile dice on the computer correctly you have to use the same calculation that actual dice use in order to get the same degree of randomness. IE: You have to have two d10 rolls and multiply one by 10 (assuming it’s not a 10 which is actually 0 at that point…) then add the other d10 to the result… Unless of course it’s 0 / 0 which is… 100. As you can see it’s a far more complex formula than simply rolling a 100 sided die. Believe it or not it definitely affects the randomness of the roll. Does it affect it to the point that it would affect a game? Nah. But it does illustrate that the computer die rollers CAN be unduly influenced by the programmer be it by using poor programming, or poor random number generators, etc.

    Me… I like dice. I like the sound they make on a hardwood table, and the suspense they engender as they bounce across the table and slowly spin to a stop. But I wouldn’t stop a player from using a well written die roller on their pda or computer.

    Random ramble… Done.

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