Sometimes an ability check is modified by special situations called advantage and disadvantage. Advantage reflects the positive circumstances surrounding a d20 roll, while disadvantage reflects the opposite. When you have either advantage or disadvantage, depending on the number of advantages or disadvantages the following bonuses are applied as stacking bonuses:
| Number of | Advantages | Disadvantages | |
|---|---|---|---|
| 1 | You roll a second d20 when you make the roll | Use the higher of the two rolls | Use the lower of the two rolls |
| 2 | You add a bonus or detriment | +2 | -2 |
| 3 | You roll a third d20 when you make the roll | Use the higher of the three rolls | Use the lower of the three rolls |
| 4 | You add a bonus or detriment | +2 | -2 |
| 5+ | You add a bonus or detriment | +1 | -1 |
For example, if you have two disadvantages and roll a 17 and a 5, you use the 5 and subtract 2. If you instead have two advantages and roll those numbers, you use the 17 and add 2.