subtracting one die from another

[addax]

Has anyone created a ruleset or have an idea as to how one would modify a ruleset to allow subtracting once die from another? A member of my group would like to run Alternity again and while we can work around a lot of stuff having the simple ability to say roll a d20 and subtract a d6 from it would speed up gameplay significantly. I've noted some other virtual tabletops that have that built in and I'm actually surprised I can't seem to do that with FG2.

Thank you for your time.

[Valarian]

There is at least one ruleset that does it. If I recall, it sets up "minus" dice as custom dice which can be used in die roll (e.g. /die 1d6+1m6 would be a d6 and a minus d6).
https://www.fantasygrounds.com/modguide/resources.xcp

[hawkwind]

this would be very handy for Fate based games

[Insanity]

The Call of Cthulhu ruleset has negative dice.

As Valarian says, i.e. m4, m6, etc...

The code is in the gameelements.xml file, and looks like this.


<customdie name="m4">
<model>d4</model>
<menuicon>customdice</menuicon>
<script>
function onValue(result)
return -result;
end
</script>
</customdie>