Put a roll string in the input. Such a string looks like, minus the [] brackets:
name #x#d#+#d#+#
The name and first number, including the "x", is optional. It states how many times to run the roll:
5x3d6 => Roll 3d6, 5 separate times.
You can include as many different dice expressions (#d#) as you want, summed together:
damage 3d6+1d8 => Roll 3d6 and 1d8, add it together. Labeled as "damage" in the output.
You can optionally include a final adder or subtractor:
1d8+1d4-3 => Roll 1d8 and 1d4, add them together, and subtract 3.
Each dice expression (#d#) can include an optional specifier afterwards. You can DROP the lowest value of dice by specifying r, the highest value of dice by specifying R or EXPLODE on a certain value or higher by specifying e or E:
6x4d6r1 => Roll 4d6 and drop the lowest die, six times (basic stats).
2d20R1 => Roll 2d20, drop the highest die (basic disadvantage).
6d6e6 => Roll 6d6, exploding on sixes.
6d6e5 => Roll 6d6, exploding on fives, and the exploded dice can also explode (up to 5 times, hard limit).
Check the "collate" box to have the die results sorted and counted by the number of times the face appeared:
6d6 (collated) => [1x1,2x3,3x6] -> 25