If you're new to tabletop RPG, the standard 7-piece polyhedral dice set can look intimidating. Seven different shapes, numbered differently, used for different purposes. This guide explains exactly what each die does, when you use it, and why all seven are included in every standard D&D dice set.
By Gideon Vance — longtime Dungeon Master and gemstone dice collector writing on dice materials, fairness, and play for EpicWinDND. Last reviewed June 2026.
What Is a Polyhedral Dice Set?
A polyhedral dice set contains dice with different numbers of faces — unlike standard cubic dice that have six faces. The term "polyhedral" refers to any three-dimensional shape with flat faces. In tabletop RPG, the standard set of seven polyhedra covers every dice roll required in Dungeons & Dragons 5e, Pathfinder 2e, Call of Cthulhu, and most major systems.
The seven shapes are the D4, D6, D8, D10, D% (percentile), D12, and D20. Each serves a different mathematical function in the game — they're not interchangeable, and each sees regular use in a typical D&D session.
The 7 Dice and What They Do
D4 — The Four-Sided Die
The D4 is a tetrahedron — four equilateral triangular faces. It's the smallest die in the set and reads differently from the others: the result is the number at the base of each face, not the top point. D4s are used for small damage rolls (daggers, magic missiles) and some healing spells.
- Faces: 4
- Common uses: Dagger damage (1d4), Magic Missile (1d4+1), Healing Word (1d4)
- How to read: Look at the number along the bottom edge, not the tip
D6 — The Six-Sided Die
The standard cube — six square faces numbered 1–6. This is the die most people have encountered before tabletop RPG. In D&D, D6s handle short sword and hand crossbow damage, as well as ability score generation (roll 4d6, drop the lowest).
- Faces: 6
- Common uses: Shortsword damage (1d6), Fireball (8d6), Hit Die for rogues/bards
- How to read: Number facing up
D8 — The Eight-Sided Die
An octahedron with eight triangular faces. The D8 is the standard die for longbow and longsword damage, and serves as the Hit Die for clerics, bards, and rogues at higher tiers.
- Faces: 8
- Common uses: Longsword damage (1d8), Cure Wounds (1d8+modifier), Cleric Hit Die
- How to read: Number at the top point
D10 — The Ten-Sided Die
A pentagonal trapezohedron — ten kite-shaped faces. The D10 appears twice in a standard set: once numbered 1–10, and once as the D% (percentile die) numbered 00–90 in tens. Together they generate 1–100.
- Faces: 10 (numbered 1–10 or 0–9)
- Common uses: Heavy crossbow (1d10), Paladin smite dice, Wild Magic Surge table (1d100)
- How to read: Number at the top
D% (Percentile Die) — The Tens D10
Identical in shape to the D10 but numbered in tens: 00, 10, 20, 30, 40, 50, 60, 70, 80, 90. Roll it alongside the standard D10 — the percentile die provides the tens digit and the D10 provides the ones digit. A roll of 70 + 3 = 73.
- Faces: 10 (numbered in tens)
- Common uses: Percentile tables, Wild Magic Surge, some class features and random encounter tables
- How to read: Add the percentile result to the D10 result to get 1–100
D12 — The Twelve-Sided Die
A dodecahedron with twelve pentagonal faces. The D12 is the barbarian's die — it's used for the Barbarian Hit Die and great axe damage. Outside those uses, it appears mainly in specific class features and some monsters.
- Faces: 12
- Common uses: Greataxe damage (1d12), Barbarian Hit Die, some bard inspiration dice at higher levels
- How to read: Number at the top
D20 — The Twenty-Sided Die
The iconic die of D&D. The D20 determines whether attacks hit, whether spells land, and whether you succeed at skill checks and saving throws. A natural 20 (rolling a 20 before any modifiers) is a critical hit on an attack. A natural 1 is a critical fail. The D20 is the most rolled die in any D&D session.
- Faces: 20
- Common uses: Attack rolls, skill checks, saving throws, ability checks
- How to read: Number at the top — the face directly pointing upward
How Often Do You Use Each Die?
Frequency varies significantly by die and character class:
- D20 — every attack, skill check, and saving throw. The most used die in every session.
- D6 — damage rolls for common weapons and many spells; Fireball alone uses 8d6.
- D8 — very common for weapon damage and healing spells.
- D10 / D% — used in damage and class features; percentile tables appear occasionally.
- D12 — barbarians use it frequently; for other classes, it appears rarely.
- D4 — less common than D6/D8, but present in some spells and small weapons.
If you only want to keep one die close at hand, it's the D20. But you'll reach for all seven regularly over the course of a session.
Reading Dice Notation
Dice rolls in D&D are written in the format XdY + Z, where X is the number of dice, Y is the die type, and Z is a modifier added to the result.
- 1d20+5 — roll one D20, add 5
- 2d6 — roll two D6 dice, add the results together
- 8d6 — roll eight D6 dice, total the results (Fireball damage)
- 1d4+1 — roll one D4, add 1 (Magic Missile damage)
When you see a damage roll like "2d8+3," it means: roll two D8 dice, add both results together, then add 3. The X number tells you how many dice to roll simultaneously.
Do You Need More Than One Set?
One 7-piece set is technically sufficient for D&D 5e — the rules assume you have exactly these dice available. In practice, having a second set is useful for high-damage characters who frequently roll multiple dice simultaneously.
Sorcerers casting Fireball (8d6) or Druids rolling multiple Shillelagh attacks benefit most from having extra D6s and D8s. Barbarians rolling great axe damage plus rage damage can exhaust their D12 and D6 supply in a single turn at high levels. Two sets of polyhedral dice cover virtually every scenario in standard D&D play.
Choosing Your First Polyhedral Set
For a first premium set, the material choice is secondary to getting the right dice shapes and a legible number font. Every set in our Best Selling Series includes all seven polyhedral shapes with clearly engraved numerals. The visual style can match your character; the function is identical across all materials.
If you're specifically buying for a new player, our Crystal Series offers complete 7-piece sets at entry-level prices — the clearest step up from the plastic dice that come in starter kits, without the care requirements of gemstone or metal.
The Unwritten Rules of Polyhedral Dice
A few things the rulebook doesn't explain about dice at the table:
- The D20 controls the table's energy. A natural 20 at a critical moment changes the atmosphere immediately. A natural 1 on a saving throw causes groans. No other die generates this reaction. The D20 is the reason players develop superstitions about specific sets.
- Some players never touch another player's dice. This is a genuine table norm in some groups — asking before picking up someone's dice is courteous in many gaming communities.
- Rolling off the table usually counts. Most tables rule that a die that falls to the floor must be rerolled. A die that lands awkwardly tilted against the tray wall is also typically rerolled. Your group's specific rules may vary.
- The "dice jail" is a real thing. Players who believe a specific die is rolling poorly will put it aside and switch to a different one. Irrational? Technically yes. Universal? Absolutely.
Understanding these unwritten norms helps new players navigate their first few sessions. The dice are the medium through which the story gets told — the rituals around them are part of the culture, not separate from it.
Frequently Asked Questions
What is a polyhedral dice set?
Seven dice in the shapes of the Platonic solids plus a percentile d10: d4 (tetrahedron), d6 (cube), d8 (octahedron), d10 (pentagonal trapezohedron), d12 (dodecahedron), d20 (icosahedron), and a second d10 numbered for percentile use.
What is each polyhedral die used for in D&D?
d4 damage for daggers and Magic Missile, d6 for ability scores and many spells, d8 for longswords and healing, d10 for rapiers and percentiles, d12 for greataxes and Barbarian hit dice, d20 for every attack/save/check, and the d100 (paired d10s) for random tables.
Why do D&D players need a d20 but rarely use a d12?
The d20 governs every attack, saving throw, and ability check — it's rolled dozens of times per session. The d12 only appears for a few weapon damage rolls (greataxe) and Barbarian hit dice, so it sees the least action of any die in the set.
What is a d100 and how do you roll it?
Two d10s rolled together — one read as the tens digit (00, 10, 20…) and one as the units. The result runs 01–100, where double 0 conventionally reads as 100. Used for random treasure tables, wild magic surges, and percentile checks.
Do all RPGs use the same polyhedral set?
D&D, Pathfinder, and most fantasy RPGs use the standard 7-piece set. Some systems require additional dice — World of Darkness uses pools of d10s, Genesys uses custom narrative dice, and FATE uses six-sided Fudge dice. Check the specific system before assuming.