Dice
Endchan has dice. Put "dice" (without quotes) in the email field of your post.
You can also specify (without quotes):
1st number: how many dice (from 1-100)
if you want to change the number of sides then add a "d"
2nd number: how many sides all die have (from 2-100)
if you want to modify the final roll then then add a "+" or "-"
3rd number: modifier that is added to the roll result, for example "18" (from -1000 to 1000)
for example: "dice 2d20" (without quotes in the email field of the post) to roll 2x 20-sided dice