standard polyhedrons six-sider sets ten-sider sets
GURPS set 1 (1d-3d) GURPS set 2 (3d-6d) GURPS set 3 (6d-10d)
Fudge set

Basic Instructions:

  1. Enter the dice you want to roll in the box, in the usual format: 1d20, 2d6-2, 1d10+1, etc.
    • Enter as many dice sets as you want, separated by commas.
    • Use 1d100 for percentile dice and dF for Fudge dice.
    • Clicking on the radio buttons underneath the box loads the box with predefined dice sets. You can use these, modify them however you wish, or enter your own.
  2. Click the Roll Dice button or hit [Enter]. Your results will be displayed in the order you specified them.
  3. The dice sets you specify will also become part of the URL of the page, so that after you click Roll Dice, you can bookmark the page, to save those dice sets. Anytime you come back to that bookmark or refresh that page, the dice will be re-rolled the same way you specified them.

Advanced Instructions:

  1. In addition to dice sets, you can specify overall modifiers that will affect only the total, not the individual rolls. For example, 1d4+1, 2d6, 2. In a pinch, you can use this page as a crude calculator, by entering plain numbers separated by commas: 4, -2, 13.
  2. Dice sets can include multiple die types and modifiers added together, like 2d6+1d4+2, 5, 1d20, 2d6-12, 1d100-1d10+1, -1d4. Dice can be added or subtracted in the set, just like modifiers.
  3. If you click on "sort dice and mods," the individual dice results and modifiers in each dice set will be displayed in order from highest to lowest. If you click on "don't sort dice and mods," the dice and modifiers will be listed in the order that you entered them. For example, if you choose to roll 2d6+1d20+2 and choose "don't sort," the results of the two d6 will appear first, followed by the results of the d20, followed by the modifier 2, possibly like so: 5, 6, 13, 2. If you had chosen to sort that result, it would have come out 13, 6, 5, 2.
  4. If you check the box next to "Average set values and die rolls," an additional line will be displayed underneath the total, showing the average of the dice sets (including their modifiers) and the average of the individual die rolls (not including their modifiers, just the individual dice, averaged together). This is mostly useful for game designers, but might be of interest to curious players.
  5. The dice format is not limited to realistic dice. If you want to roll 2d37, you can. You can also include modifiers with decimal values (2d37+1.23). This page does not (yet) handle decimal-value dice or adding/subtracting a value from each individual die within a set.
  6. To save time, specify the dice sets for all the dice you roll during a game, and bookmark it. Then, whenever you need to roll any dice, just roll all of them at once by refreshing the page, and only look at the value of the dice you need at that moment.
  7. You can specify labels for your dice sets, buy putting them in brackets before the set, like so:
    [George's to-hit] 1d20+4, [George's damage] 1d4, 1d6, [Betty's to-hit] 1d20, [Betty's damage] 1d8+2, 1d12.
    Once you have all your dice sets set up just the way you like them, add in labels in the appropriate places, to remind you which dice are for who and what.
  8. If you need multiple combinations of dice sets, make one, bookmark it, then make another, and make a separate bookmark. That way, those two sets are each one click away.
  9. This page contains all the code it needs to run, so it doesn't need to run from a web server to work. If you want, you can save a copy of this page to your hard drive, and continue to use it without an Internet connection.

How truly random is this thing, anyway?

Well, I imagine that depends on a lot of factors. This page runs JavaScript within your web browser, so I'm guessing it depends a lot on how good a job was done by the people who wrote those two things.

See below for links to load separate pages that do a little test to see how good this random number method really is. I'm no mathematician, so I can't guarantee the validity of this test, even though it seems to provide very pleasing results to me. Does this mean the dice roller is "truly random"? All the computer references I've read on the subject say that computers are incapable of generating truly random numbers without some sort of hardware specifically made for that purpose. However, since the test pages seem to indicate that this randomizer gives an even spread of results over time, and since I imagine that's exactly what most fair-minded gamers would want to see, I hereby proclaim this dice roller Good Enough for Gaming!

What this test page does is generate 100,000 random numbers between 1 and 100, then counts how many of each number appears during the test. From my test runs using my browser (Netscape 7), it looks as if all the numbers are fairly evenly represented.

Here's another page that does the same test for 1d6.