Advantages of using different die for base numbers.

[Lago PARANOIA]

So I can understand the merits of using a d20 and I sort of understand why using a d6 is good, but what's the point of those systems that base everything on d8 or d10?

[TavishArtair]

A d10 has 10 faces, and thus naturally produces results numbered 1 through 10.

... that's it, man.

[Username17]

Larger Dice:

• Roll Farther
  Cost More Money
  Produce More Potential Results

The d4 doesn't roll far enough. I used to be able to roll a d4 so that it would land the way I wanted it to 2 times out of three after hitting the table and turning over (any jackass can toss a d4 so that it hits the table with the four sticking up and just slides a meter or more). The d30 rolls too far. That thing is a fucking useless golf ball that rolls right off the table and under the couch.

What you define as your personal sweet spot between those is largely personal taste.

-Username17

[RandomCasualty2]

Mainly different dice are used to generate more results. In a straight up die + modifiers addition system (like d20) You're basically worried about a couple things: Bell curve and RNG range.

The more dice you use, the greater the bell curve, so using larger dice can flatten out the curve while keeping your RNG range higher. 3d6 and 1d20 generate a similar result range, but the bell curve is much more pronounced in 3d6.

If you're running in a multi-die success system, like Shadowrun or White wolf, then you're interested primarily in granularity of success numbers. If your system has a fixed target number, you might as well use d6s. There's generally no point to use d10s or any of those crazy other dice. The new storyteller system has some odd mechanics where dice do funny stuff on 9s or 10s, so that's partial justification, but really, things like that are probably not great game design, as a success system in general creates a wide range of effects. So adding crazy crap like "If you use a shotgun, you get to reroll all your 10s for more successes" just makes the math harder, but doesn't even accomplish much.

If you're doing a variant TN like old SR and White wolf, then using larger dice actually makes sense, because you want to control how quickly that TN explodes off the scale. In SR3, a single +1 or +2 penalty to TN was utterly crippling because you were only on a D6. But having your TN go from a 6 to an 8 on a d10 isn't so bad.

But given that variant TN systems are basically phased out, generally this is less of a concern.

[Heath Robinson]

Not to mention that naive dice explosions create oddities like P( 6) = P( 7) under variable TN systems, which you encounter much less frequently in play with larger dice as they have a greater range. Smaller dice generally mean that you roll more times per roll, as explosions are more common.

[angelfromanotherpin]

The d30 rolls too far. That thing is a fucking useless golf ball that rolls right off the table and under the couch.

The store I work in sells two different models of d100. One is a sphere that actually has 100 numbers inscribed upon it and has sand inside it to keep it from going forever. The other is a small d10 inside a larger transparent d10 with the 0s tacked on so you know it's the 10s digit. The latter is much more popular.

[Draco_Argentum]

The other problem with d4s is that if you lose them you find them exactly the same way you find a caltrop.