About the four-sided die
The d4 is a tetrahedron: four equilateral triangles, the simplest of the five Platonic solids. Because it always lands on a face with a point sticking up, it has no "top face" to read. Most modern d4s print three numbers on every face, one by each corner, and you read the number at the top point — every visible face shows the same number there. Some older designs print the number along the bottom edge instead. The 3D d4 here uses the top-reading style.
What the d4 is used for
In Dungeons & Dragons the d4 rolls small amounts: a dagger, club, sling or dart deals 1d4 damage, each dart of Magic Missile deals 1d4+1, and a Potion of Healing restores 2d4+2 hit points. It also turns up in board games as a compact way to pick one of four options.
D4s are notoriously painful to step on — one more reason to keep a virtual one handy.
Two d4s and their odds
| Total | Ways | Chance | Odds | This or higher |
|---|---|---|---|---|
| 2 | 1 | 6.25% | 1 in 16 | 100% |
| 3 | 2 | 12.5% | 1 in 8 | 93.8% |
| 4 | 3 | 18.8% | 1 in 5.3 | 81.3% |
| 5 | 4 | 25% | 1 in 4 | 62.5% |
| 6 | 3 | 18.8% | 1 in 5.3 | 37.5% |
| 7 | 2 | 12.5% | 1 in 8 | 18.8% |
| 8 | 1 | 6.25% | 1 in 16 | 6.25% |
No d4? Make one from other dice
- From a d8: roll it and halve, rounding up (1–2 → 1, 3–4 → 2, 5–6 → 3, 7–8 → 4).
- From a d6: roll it and re-roll any 5 or 6.
- From a d20: divide by 5 and round up.
Or simply roll one here — it is exactly fair.