Where Can I Buy a Dicebag +5?

[Stormonu]

They do sell loaded polyhedral dice (Unfortunately, I had a player who purposely bought such dice and tried to use them in a game), so unless these are transparent dice, there's a slim chance something is up with them.

I suppose the easiest way to find out if they are tainted is to have a "session" where you just sit down and roll them about a hundred times (or more) and record the results. If they're skewed, a large die roll sample should bear this out.

Another method would be check to see if the dice has been shaved - this is a method of removing a tiny bit from the various faces of the dice to bias the result. If I remember correctly, the shaved faces would be the ones opposite the high sides (so the "low" numbers are heavy and end up on the bottom).

I also seem to recall some method involved with immersing the dice in water to determine if they are biased (with weights), but my google-fu isn't all that great tonight.

Gamescience also has a good (though long) spiel about dice and how they generally have some bias due to the imperfect manufacturing of most dice (of course, save for Gamescience dice). There is a possibility the dice may be biased without it having been bought specifically for that purpose.

 

[sjmiller]

Unfortunately, there’s no way that I know of to conclusively check, and asking/telling/demanding that he not use them seems petty, since without definitive proof it just makes me look jealous of his presumed luck.

There is a way to check the dice, if the other player is willing to cooperate. The test you want to conduct is called a Chi-Square Test. It involves rolling each die a large number of times, recording the rolls for each die. Then you do some quick math, consult a table, and you can tell if the die is biased or not. If you have the Dragon Magazine Archive there is an article there. Failing that, look up Chi-Square Test and you will find a number of sites that show you how to do it.

Of course, this does require the other player to either let you roll the dice a lot or roll them himself. Still, there is a way to get a definitive answer.