How do I make R20 regard a D10 with a range of 0-9?

The game system I'm playing (CD10) uses 1D10 as the core die. A core mechanic of the game is that the D10 has a range of 0-9. 0 means an automatic failure and re-rolls to avoid a fumble. 9 explodes for additional success. How would I go about making such a roll in R20? I can't figure out how to make R20 consider a D10 as 0-9, rather than 1-10. The rest I could probably figure out, but that one stumps me.

just a basic 1d10-1 will give you a base result of 0-9

This is true, but if I want to add mechanics for the exploding 9, it will explode on 10, not 9. That's a problem. I need R20 to roll a 0-9 D10 so I can use the ! command to make it explode on 9. The maths becomes all kinds of screwed up if it explodes on 10. 

You can use d10!9-1 The exclamation mark makes it explode, the 9 after the ! makes it explode only if a 9 is rolled.  The only odd thing will be if you roll a 10, the result will be 9, so you either count that as an 8, a 9 (where the re-roll was a 0) or re-roll it. That same mechanic will apply on the exploding as well...for example you roll a 9 and the reroll is a 10, the result will be 18. To show you what I mean: The other option would be to use a rollable table (though you can't automate the re-roll with that) or an API which is the only way to get the die mechanic perfect.

I'll fiddle around with your method, but I think in the end it might just be that I'm gonna have to make an API. Thanks for the help!

Remember that the API requires a pro subscription to be enabled.

Another option would be to simply count the 10 as 0... Then you could just do... /r 1d10!9

Finderski said: Another option would be to simply count the 10 as 0... Then you could just do... /r 1d10!9 This is likely what we'll end up doing and simply subtract the 10's ourselves from the result. It's less work than any other option, and we wanna get going, not get stuck writing code for a week. Thanks for the advice! :)

Tobias L. said: Finderski said: Another option would be to simply count the 10 as 0... Then you could just do... /r 1d10!9 This is likely what we'll end up doing and simply subtract the 10's ourselves from the result. It's less work than any other option, and we wanna get going, not get stuck writing code for a week. Thanks for the advice! :) Glad to help... Also, just had another thought, if you really want to make sure the 10's stand out (even if there are modifiers to the roll), you could use /r 1d10!9cs9cf10 That will color the die roll red if a 10 was rolled, and green if a 9 was rolled. That will also allow you to use inline rolls like this: /em rolls some trait and gets [[1d10!9cs9cf10]] That will highlight the total in Green if a 9 was rolled, red if a 10 was rolled, or blue if a 9 and a 10 were rolled (for example, the first roll is a 9 and the second roll was 10) In that case, you'd need to remember that 19 = 9. :) Hovering over the result will also show the individual die results: