D3

D3.

The D3...

Not much to say about it.

Warhammer 40k uses D3's every once in awhile - Rending, Manticores, & other cases such as +D3 attacks, 2 + D3 objectives, etc. Most of the time, they don't actually use a D3 - they just roll a d6, at which points two schools of thought engage in a holy war:

• Some substract 3 from any result that's 4 or higher. So, for example, a 5 becomes a 2.
• Others divide the result by two, rounding up. So, for example, a 5 becomes a 3.

The 40k rulebook explicitly proselytizes the latter, which means the former is heresy.

Actual D3's come in two major flavours: The weird triangular nublette things seen to the right which are largely used by people who think having weird dice makes you interesting, and D6es which had 1,2 and 3 written on them twice used by people who like to build things out of dice.

Since you can readily simulate a d3 result easily enough without obtaining extra dice why in the hell would you bother?