This is what I found. The exploding rolls where not working at the time this was introduced. I don't know if that has changed. Feel free to play with it here.
'This is a fairly simple implementation. It's off the shelf, and unsupported, so if parts of it don't work I can't fix it, nor can I add to it. So it is what it is!
Include BB code in your posts in Xdy+z format. Note Z can be +,-,*, or /.
Basic bb code is {roll}. Just gives the total: (3d6+6)[15]
Use {rollv} to list each individual roll as well as the total: (3d6+6)[2][5][4](11) .
Use {rollo} for exploding (open) dice which rerolls dice which come up max.
Include a note, like {roll=Bob's Attack Roll}1d20{/roll}: Damage Roll - (2d8+4)[4][4](8)
Use a letter b to sum only the best b results, such as {roll}4d6b3{/roll} which rolls 4d6 and adds the best three.
You cannot add dice rolls with an edit. So once you submit your post, you can't sneakily change the rolls.
Read more:
http://www.enworld.org/forum/showthread.php?340379-Test-the-dice-roller#ixzz35CqTSc'