Support for Level Up D&D

[SouthamptonGuild]

Hi!

There is a new system which kickstarts on 5th October and will be available by end of Nov 21.

It uses D&D 5e but with the following changes.

The standard roll may add or subtract an "expertise die". The expertise die starts at a D4 but when you gain other sources of expertise may go up a die size, e.g. if you have expertise and you gain bardic inspiration, then instead of adding 2D4, you add D6 to the roll.

Subtraction would be from minor penalties or spells.

It is obviously possible to type in !roll 2d20 +$Abi k1 for advantage, and then !roll d4 and do the math manually. But I would like something like:
!roll 2d20 +$abi k1 +/-exp D4

To output the roll with advantage, adding the ability modifier and then adding or subtracting the expertise die as required.