A creature can perform a Challenge Roll with multiple stacks of ADV or DIS.

Summing ADV and DIS:
- All stacks of ADV and DIS are combined.
- Each stack of ADV or DIS grants an additional die roll beyond the standard roll.

Effect on Rolls:
- Most ADV / DIS rolls mostly effect Challenge Rolls.
- However, ADV / DIS can not only d20 rolls but also Damage Rolls or other types of rolls (such as d8, d12, etc.).

Rolling with ADV or DIS:
- For ADV, you roll a number of dice equal to 1 + the total number of ADV stacks and take the highest result.
- For DIS, you roll a number of dice equal to 1 + the total number of DIS stacks and take the lowest result.

Examples:
- ADV: With 2 stacks of ADV, you would roll 3d20 and take the highest of the three rolls.
- DIS: With 3 stacks of DIS and a base roll of d8, you would roll 4d8 and take the lowest of the three rolls.