# Dice Roller

### From Roll20 Wiki

1d20+3

## Useful Rolls

The dice roller is very easy to use, simply type in the formula in the box and press enter. Roll20 features support for a wide array of dice mechanics. For the complete list, visit this page.

#### Exploding Dice

With exploding dice, if you roll the maximum number on the dice (a 6 with a d6, a 10 with a d10, etc.) you get to re-roll again and add the additional roll to your total for that roll. If the additional roll is also a maximum number, you get to keep rolling!

To perform a roll with exploding dice, just add an exclamation point after the number of sides in the formula. For example, `/roll 3d6!`

would roll 3 d6 dice with exploding re-rolls. You can also define the exploding point for the dice using the greater-than and less-than symbols. For example, `/roll 3d6!>4`

would explode on any dice greater-than or equal-to 4. `/roll 3d6!3`

would explode only if a 3 is rolled.

#### Drop/Keep

Some game systems ask you to roll a large number of dice, and then either drop a certain number of the lowest rolls, or keep only a certain number of the highest rolls. Roll20 supports this type of roll through the `d`

and `k`

commands, respectively.

For example, you might roll 8 d100 dice and only be allowed to keep the top 4 rolls. In Roll20 this would be expressed with `/roll 8d100k4`

. When Roll20 prints the output from that roll, you'll see each individual d100's rolled value, and all but the top 4 rolls will be greyed out. Roll20 will then give you the total of the top 4 rolls. Doing a roll to drop the 3 lowest rolls would be very similar: `/roll 8d100d3`

. Again, the value of each dice rolled will be displayed, with the 3 lowest rolls greyed out.