Dice Breakdown

Standard Dice

d4 (Tetrahedron)

• Sides: 4
• Range: 1-4
• Average: 2.5
• Common Uses:
  • Damage for daggers, darts, slings
  • Healing potions (minor)
  • Spell components (Magic Missile)
  • Small creature hit dice

d6 (Cube)

• Sides: 6
• Range: 1-6
• Average: 3.5
• Common Uses:
  • Damage for shortswords, shortbows, fire bolt cantrip
  • Hit dice for wizards, sorcerers
  • Initiative modifiers
  • Most common damage die in early levels

d8 (Octahedron)

• Sides: 8
• Range: 1-8
• Average: 4.5
• Common Uses:
  • Damage for longswords, battleaxes, crossbows
  • Hit dice for clerics, druids, monks, rogues, warlocks
  • Healing spells (Cure Wounds)
  • Medium weapon damage

d10 (Pentagonal Trapezohedron)

• Sides: 10
• Range: 0-9 (standard d10)
• Average: 4.5
• Note: When used alone, 0 typically counts as 10
• Common Uses:
  • Damage for heavy crossbows, pikes
  • Cantrip damage scaling
  • Component of percentile dice (d100)
  • Random tables and encounters

d10 (Percentile/Tens Die)

• Sides: 10
• Range: 00, 10, 20, 30, 40, 50, 60, 70, 80, 90
• Markings: 00-90 in increments of 10
• Purpose: Used with standard d10 to create d100 rolls
• Common Uses:
  • Paired with units d10 for percentile rolls
  • Wild Magic tables
  • Random encounter generation
  • Loot tables

d12 (Dodecahedron)

• Sides: 12
• Range: 1-12
• Average: 6.5
• Common Uses:
  • Damage for greataxes, lances
  • Hit dice for barbarians
  • Wild Magic Surge tables
  • Less commonly used overall

d20 (Icosahedron)

• Sides: 20
• Range: 1-20
• Average: 10.5
• Common Uses:
  • THE core die of D&D
  • Attack rolls
  • Ability checks
  • Saving throws
  • Skill checks
  • Initiative rolls

d100 (Percentile Dice)

• Composition: Two d10s - one percentile die (00-90) and one units die (0-9)
• Range: 0-99 (0 May count as 100)
• Average: 49.5
• How to Read:
  • Percentile die shows tens place (00, 10, 20, etc.)
  • Units die shows ones place (0, 1, 2, etc.)
  • Example: 30 + 7 = 37, (or may 00 + 0 = 100)
• Common Uses:
  • Random encounter tables
  • Loot generation
  • Wild Magic effects
  • Critical hit/fumble tables
  • Percentage-based abilities

Dice Combinations and Notation

Standard Notation

• XdY: Roll X dice with Y sides
  • 1d6 = Roll one six-sided die
  • 3d8 = Roll three eight-sided dice and add them together
  • 2d10 = Roll two ten-sided dice and add them together

Modifiers

• XdY+Z: Add a fixed number
  • 1d6+3 = Roll 1d6 and add 3
  • 2d8+5 = Roll 2d8 and add 5

Advanced Notation

• XdY-Z: Subtract a fixed number
• XdYkH: Keep highest (advantage-like mechanics)
  • 2d20kH1 = Roll 2d20, keep the highest
• XdYkL: Keep lowest (disadvantage-like mechanics)
  • 2d20kL1 = Roll 2d20, keep the lowest
• XdYr: Reroll specific numbers
  • 1d8r1 = Roll 1d8, reroll 1s
• XdYe: Exploding dice (reroll max values and add)
  • 1d6e = Roll 1d6, if you get a 6, roll again and add

Specific Uses in D&D 5e

Combat

Action	Dice Used
Attack Roll	1d20 + modifiers
Damage Roll	Weapon-specific + modifiers
Critical Hit	Double the damage dice
Death Saves	1d20 (10+ succeeds)

Hit Dice by Class

Class	Hit Die
Barbarian	d12
Fighter, Paladin, Ranger	d10
Artificer, Bard, Cleric, Druid, Monk, Rogue, Warlock	d8
Sorcerer, Wizard	d6

Weapon Damage

Weapon Type	Damage Die
Simple Melee	d4-d6
Martial Melee	d6-d12
Simple Ranged	d4-d8
Martial Ranged	d6-d10

Spell Damage Progression

Spell Level	Typical Damage
Cantrip	1d4-1d10 (scales with level)
1st Level	1d4-3d6
2nd Level	2d6-4d6
3rd Level	3d6-8d6
Higher Levels	Increases significantly

Other Systems

Call of Cthulhu

• Primary Die: d100 (percentile)
• Mechanic: Roll under your skill value to succeed
• Skill Range: 1-100 (higher is better)
• Success Levels:
  • Regular Success: Roll under skill value
  • Hard Success: Roll under half skill value
  • Extreme Success: Roll under one-fifth skill value
  • Critical Success: Roll 01
  • Fumble: Roll 96-100 (if skill is 50+) or 100 (if skill is under 50)
• Example: Psychology skill of 60 means success on 01-60, hard success on 01-30, extreme success on 01-12

Fate/Fudge Dice (dF)

• Sides: 6 (marked with +, +, blank, blank, -, -)
• Range: -4 to +4 (rolling 4dF)
• Used in: Fate Core, Dresden Files RPG

Advantage/Disadvantage

• Mechanic: Roll 2d20, take higher (advantage) or lower (disadvantage)
• Probability: Significantly shifts odds compared to flat 1d20
• Used in: D&D 5e extensively

Step Dice (Savage Worlds)

• System: Different die types for different skill levels
• Progression: d4 → d6 → d8 → d10 → d12
• Mechanic: Exploding dice (aces)

Pool Systems

• Mechanic: Roll multiple dice, count successes
• Examples:
  • World of Darkness: d10 pools
  • Shadowrun: d6 pools
  • Genesys: Custom narrative dice

Special Dice Types

Narrative Dice

• Boost/Setback Dice: Add positive/negative elements
• Proficiency/Difficulty Dice: Core resolution mechanics
• Used in: Star Wars RPG, Genesys

Polyhedral Variants

• d3: Three-sided (rare, usually simulated with d6÷2)
• d5: Five-sided (very rare, usually d10÷2)
• d7: Seven-sided (theoretical, achieved through complex rolling)
• d14: Fourteen-sided (uncommon, exists but rarely used)
• d16: Sixteen-sided (uncommon, square-based pyramid)
• d24: Twenty-four-sided (deltoidal icositetrahedron)
• d30: Thirty-sided (rhombic triacontahedron)

Specialty Gaming Dice

• Poker Dice: Six-sided with card faces (9, 10, J, Q, K, A)
• Crown and Anchor: Naval gambling game dice with symbols
• Bunco Dice: Standard d6 but used in specific party game
• Liar’s Dice: Standard d6 used with cups for concealment
• Yahtzee Dice: Five standard d6 for the classic game

Location/Direction Dice

• Hit Location Dice: For combat systems (d20 with body parts)
• Scatter Dice: Shows direction and distance for area effects
• Compass Dice: Eight-sided with cardinal/ordinal directions
• Weather Dice: Custom faces for weather generation

Electronic Dice

• D&D Beyond Dice Roller
• Roll20 Virtual Dice
• Physical electronic dice

Digital Dice Tools

Online Rollers

• Roll20: Full virtual tabletop with dice
• D&D Beyond: Character sheet integration
• Foundry VTT: Advanced dice mechanics
• Discord Bots: Quick rolls in chat

Mobile Apps

• Dice by PCalc
• RPG Simple Dice
• DiceBox
• Dice Roller by b.freq

Browser Extensions

• Chrome D&D Dice Roller
• Firefox Dice Roller

Probability and Statistics

Single Die Probabilities

Die	Min	Max	Average	Notes
d4	1	4	2.5
d6	1	6	3.5
d8	1	8	4.5
d10	0	9	4.5	0 often treated as 10 when used alone
d12	1	12	6.5
d20	1	20	10.5
d100	0	99	49.5	Uses two d10s

Multiple Dice Probabilities

• 2d6: Average 7, bell curve distribution (7 most likely)
• 3d6: Average 10.5, tighter bell curve
• 1d12 vs 2d6: Same average (6.5 vs 7), but 2d6 more consistent

Advantage/Disadvantage Impact

• Advantage: ~+5 bonus equivalent on average
• Disadvantage: ~-5 penalty equivalent on average
• Effect increases for middle target numbers (10-15)

Quick Reference Tables

Common Damage by Level

Character Level	Expected Damage Per Round
1-4	5-10 damage
5-10	10-20 damage
11-16	20-35 damage
17-20	35+ damage

Difficulty Class Guidelines

Difficulty	DC	Description
Very Easy	5	Nearly everyone succeeds
Easy	10	Most people succeed
Medium	15	Typical challenge
Hard	20	Difficult for most
Very Hard	25	Only experts succeed
Nearly Impossible	30	Legendary difficulty

Tips for DMs

Dice Management

• Keep dice organized by type
• Have backup dice for players
• Consider digital alternatives for complex rolls
• Use dice trays to prevent scatter

When to Use Different Dice

• d4: Small damages, minor effects
• d6: Standard effects, common damages
• d8: Medium effects, healing
• d10: Heavy damages, percentiles
• d12: Maximum damages, rare effects
• d20: All major resolution

Homebrew Considerations

• Maintain mathematical balance
• Consider probability curves
• Test new dice mechanics thoroughly
• Keep notation clear and consistent