D&D Dice Roller

About the D&D Dice Roller

Built for Dungeons & Dragons, this roller handles the common 5e dice patterns in one place. You can roll attacks with advantage or disadvantage, combine weapon dice with bonus damage dice, compare the result against AC or DC, and detect natural 20s and natural 1s automatically.

Presets cover the usual D&D cases such as attack rolls, ability score generation, weapon damage, Fireball, Sneak Attack, and Eldritch Blast. You can also build a custom dice expression when the spell or feature does not fit a preset.

That makes it a quick replacement for table dice when you want the math done immediately and the result still readable in D&D terms.

When This Page Helps

D&D turns a lot of small dice rules into one combat turn: attack roll, crit logic, damage dice, and situational modifiers. Keeping those pieces together in one roller saves time and reduces misreads when the table is moving quickly.

The reference tables also make it easier to compare common DCs, attack thresholds, and standard damage expressions without opening another tab or flipping through notes.

How to Use the Inputs

1. Click a D&D preset or build a custom dice expression.
2. Add multiple dice groups for combined damage (e.g., weapon + sneak attack).
3. Set your total modifier (ability + proficiency + bonuses).
4. Select advantage, disadvantage, or normal roll.
5. Choose roll type: attack (nat 20/1 rules), ability check, or damage.
6. Enter the DC or AC target for pass/fail checking.
7. Roll and check for natural 20s (critical hits) or natural 1s (misses).

Example Calculation

Tips & Best Practices

• Set quick presets for your character's common actions to speed up combat.
• The DC table shows your exact chance of success — use it to decide when to use Inspiration.
• For Halfling Lucky trait, reroll natural 1s manually by clicking Roll again.
• Great Weapon Master: -5 to hit (+5 to modifier means set mod to original-5), +10 damage.
• Sneak Attack dice increase every odd Rogue level: 1d6, 2d6, 3d6... up to 10d6 at level 19.
• For mass combat, batch roll isn't available here — use the standard dice roller for that.

D&D Attack Resolution

Every attack in D&D 5e follows the same core mechanic: roll d20 + attack modifier, compare to target's AC. If you meet or exceed the AC, you hit. Then roll damage dice + ability modifier. Critical hits (natural 20) double all damage dice but not modifiers.

The beauty of bounded accuracy means that a +1 bonus is always meaningful — it converts exactly 5% of misses into hits. This is why magical weapons with even a +1 bonus are prized treasures in the 5e economy.

Advanced D&D Dice Mechanics

Several D&D features modify dice beyond simple addition. Bardic Inspiration adds a die (d6 to d12) to a roll after seeing the result. Portent (Divination Wizard) replaces a d20 roll entirely. Savage Attacker lets you reroll weapon damage and take either result. Understanding these stacking interactions is key to optimization.

The Lucky feat stands out: three times per day, you can roll an extra d20 on any attack, check, or save. With advantage, this effectively gives you "super advantage" (best of three).

Probability of Combat Outcomes

Against AC 15 with +7 to hit: base 65% hit rate, 5% crit. With advantage: ~88% hit, 9.75% crit. Against AC 20 with +7: base 40%, with advantage ~64%. These numbers drive tactical decisions — knowing your exact hit rate helps determine whether Power Attack, Sharpshooter, or Great Weapon Master is worth the -5 penalty in any given situation.

Frequently Asked Questions

• How does advantage work in D&D 5e?

  Roll two d20s and take the higher result. Multiple sources of advantage don't stack — you only ever roll two dice. Advantage and disadvantage cancel each other out.

• What happens on a natural 20 attack?

  It's an automatic hit regardless of AC, and it's a critical hit. You roll all damage dice twice (but add the modifier only once). Some features like Brutal Critical add extra dice on crits.

• How do I calculate my attack modifier?

  Attack mod = ability modifier (STR for melee, DEX for ranged/finesse) + proficiency bonus (starts at +2, maxes at +6). Magic weapons add their bonus too.

• What does proficiency bonus mean?

  Your proficiency bonus is level-based: +2 at levels 1-4, +3 at 5-8, +4 at 9-12, +5 at 13-16, +6 at 17-20. It applies to attack rolls, saving throws, and skill checks you're proficient in.

• Can I use this for stat generation?

  Yes. Use the 4d6 drop-lowest preset and roll six times to generate a standard ability score array.

• How do I roll a critical hit damage?

  For crits, double your dice count (e.g., 2d8 instead of 1d8 for longsword) and add the modifier once. Use the multi-group dice system to add all dice together.