Dice Roller - Roll Dice Online Free
Roll virtual dice online. Choose from D4, D6, D8, D10, D12, D20 and custom sides. Roll multiple dice at once with instant results and roll history.
Formula
Roll = Random(1 to Sides) for each die, then sum + modifier
Each die generates a random integer from 1 to its maximum face value. Multiple dice are summed together, then any modifier is added to produce the final result.
Worked Examples
Example 1: D&D Attack Roll
Problem: A fighter with +7 to hit attacks an enemy with 15 AC. What does he need to roll?
Solution: Attack Roll = d20 + attack modifier\n\nTo hit AC 15 with +7 modifier:\nNeed: d20 + 7 ≥ 15\nd20 ≥ 15 - 7 = 8\n\nMust roll 8 or higher on d20\nProbability: 13/20 = 65% chance to hit\n\nNatural 20 always hits (critical!)\nNatural 1 always misses
Result: Need to roll 8+ on d20 (65% chance)
Example 2: Character Stat Generation
Problem: Generate ability scores using 4d6 drop lowest method.
Solution: Roll 4d6, remove lowest die, sum remaining 3.\n\nExample rolls: 4, 2, 6, 5\nDrop lowest (2): 4 + 6 + 5 = 15\n\nStatistical properties:\n- Minimum: 3 (all 1s after drop)\n- Maximum: 18 (all 6s)\n- Average: ~12.24\n- Mode: 13\n\nRepeat 6 times for all abilities.\nThis method produces higher than average scores.
Result: Typical set: 15, 14, 13, 12, 10, 8
Example 3: Damage Calculation
Problem: A rogue with 4d6 sneak attack hits with a shortsword (1d6+4). Calculate damage.
Solution: Weapon damage: 1d6 + 4 (Dex modifier)\nSneak attack: 4d6\n\nTotal: 5d6 + 4\n\nMinimum: 5 + 4 = 9 damage\nMaximum: 30 + 4 = 34 damage\nAverage: 5 × 3.5 + 4 = 21.5 damage\n\nOn a critical hit, roll all dice twice:\n10d6 + 4 = average 39 damage!
Result: Average 21.5 damage (9-34 range)
Frequently Asked Questions
What dice are used in Dungeons & Dragons?
D&D uses a standard 7-dice set: D4 (small weapon damage), D6 (fireball, sneak attack), D8 (longsword damage), D10 (heavy crossbow), D12 (greataxe), D20 (attack rolls, saving throws, ability checks - the most important die), and D100/percentile (random tables). The D20 is central to the d20 system - you roll it for almost every action and add modifiers.
How do I roll with advantage or disadvantage?
In D&D 5e, advantage means rolling 2d20 and taking the HIGHER result. Disadvantage means rolling 2d20 and taking the LOWER result. Advantage comes from favorable conditions, ally help, or certain abilities. Disadvantage comes from bad conditions, difficult situations, or penalties. They cancel each other out - any amount of advantage with any disadvantage means normal roll.
How does dice notation work (like 2d6+3)?
Dice notation follows the pattern: [number of dice]d[sides]+[modifier]. Examples: 2d6 = roll two six-sided dice and add them. 1d20+5 = roll one d20, add 5 to the result. 4d6 drop lowest = roll four d6, remove the lowest, sum the rest (common for character stat generation). 2d10×10 = roll 2d10 and multiply by 10. This notation is universal across most tabletop RPGs.
Is online dice rolling truly random?
Online dice rollers use pseudo-random number generators (PRNGs), which are deterministic algorithms that produce sequences appearing random. For gaming purposes, they're more than fair enough - the sequences pass statistical randomness tests. Physical dice can actually be LESS random due to manufacturing imperfections, worn edges, or rolling technique. For cryptographic security, specialized hardware random number generators are used.
What are percentile dice (D100)?
Percentile dice generate numbers 1-100. You can roll an actual d100 (100-sided die), or use two d10s: one for tens digit (0-9 representing 00-90) and one for ones digit (0-9). Rolling 00 and 0 equals 100, not 0. Used for percentage-based tables: 'Roll d100, on 01-15 you find treasure.' Some systems like Call of Cthulhu use percentile dice as the core mechanic.
How do different dice affect game feel?
Dice choice significantly affects gameplay feel. D20: High variance, swingy results - a peasant can sometimes beat a master. D100: Granular probabilities, skills matter more incrementally. 2d6 or 3d6: Bell curve means average results are common, extremes rare - more predictable. Dice pools (multiple dice, count successes): Scale smoothly with ability, success is probability-based. Game designers choose dice systems to create specific dramatic effects.