In Dungeons & Dragons, advantage and disadvantage are significant game mechanics. When rolling with advantage, you roll two D20s and take the higher result. This could be due to a beneficial spell, a special ability, a magical item, or the Dungeon Master's discretion based on the circumstances. On the other hand, rolling with disadvantage means rolling two D20s and taking the lower outcome. This generally happens when the situation is particularly challenging for the character. Statistically, while the average D20 roll is 10.5, rolling with advantage or disadvantage shifts this average. An advantage roll averages at 13.9, while a disadvantage roll averages at 7.1. These mechanics introduce additional layers of strategy and unpredictability, reflecting the dynamic nature of the D&D world.