1D6E

1D6E is a dice notation used in tabletop gaming to indicate rolling a single six-sided die with exploding (open-ended) results. The E denotes that when the die shows its maximum value, the die is rolled again and the new result is added to the previous total; if that subsequent roll is again a 6, the process repeats indefinitely until a non-6 comes up. This mechanic can be described as an exploding d6.

In practice, 1D6E increases the average outcome compared to a standard 1D6 roll. The expected value is 21/5, which equals 4.2. The distribution is heavier on higher results and the chance of achieving very high totals exists due to the chaining of extra rolls. This can influence game pacing by creating moments of sudden, high payoff.

Usage appears in some homebrew or indie systems and puzzle contexts; it is not a universal standard. It is often discussed in relation to other open-ended or exploding-dice mechanics, including variants where explosions are capped after a fixed number of repeats or where the explosion adds only part of the subsequent roll.

Variations may adjust how explosions occur, such as limiting the number of possible explosions, altering the trigger value, or changing whether the added value includes the original explosion or only the subsequent roll. Overall, 1D6E is a compact way to encode a high-variance mechanic that can significantly affect outcomes and risk assessment in a game.