Free Online D&D Dice Roller | Copycats Handmade Dice

Our roller uses a cryptographic random number generator (from your browser) plus a technique called modulo-rejection to ensure every face is picked fairly and uniformly.

>>What is cryptographic randomness?

It’s high-quality randomness provided by your device’s operating system and browser. It’s designed for security, drawing on system entropy (timing jitter, hardware noise, etc.) to produce numbers that are totally unpredictable and suitable for SERIOUS use. Things like secure password generators, banks and gambling sites use this powerful method for various important jobs.

We use it for rolling initiative :).

>>What’s “modulo rejection,” and why use it?

When you map a big, random, generated number down to a die face (like 1–20), a simple “remainder” will almost always favor some faces. This is called modulo bias.

Rejection sampling fixes that:

1. Take a random number.
   
2. If it falls in the tiny “overflow” range that would make the mapping uneven, discard it and draw again.
   
3. Otherwise, map it to 1–N.

This bit of math guarantees each face has exactly the same odds of appearing in our dice roller. Thanks Mr. Santor!

(Bonus: We don’t send or store any roll data. Everything happens locally in your browser.)

When you roll with Advantage, you roll two d20s and keep the higher one. With Disadvantage, you keep the lower one. This applies to attack rolls, ability checks, and saving throws.

Example: You roll 7 and 16 with +7 to hit against AC 15 → keep 16. 16+7=23 vs 15 → Success.

Turn Crit on when your attack roll crits (e.g., a natural 20 or a confirmed crit by your table rules). It doubles your damage dice (not your modifiers) for non-d20 damage.

Example:

• Longsword 1d8+4 on a crit → 2d8 + 4 (the +4 isn’t doubled).
  
• Fireball 8d6 (save for half) → usually no crit; leave this off.

These adjust the final damage total (after your Damage mod). 5e rounds down.

• Half (save): ×0.5 (round down).
  
• Resist+Save ¼: ×0.25 (round down).
  
• Vulnerable ×2: ×2.

Examples:
• Damage total 30, Resist+Save ¼ → 7.
• Damage total 30, Half (save) → 15.
• Damage total 30, Vulnerable ×2 → 60.

Modifiers add or subtract fixed bonuses to your roll.

• d20 mod applies to each kept d20 (attack/check/save/initiative), after Advantage/Disadvantage is resolved.
  
• Damage mod applies once per damage roll (e.g., your STR/DEX bonus). On a crit, only the damage dice are doubled. The Damage mod is not doubled.
  
• You can enter negative numbers (e.g., −1).
  
• For multiple attacks/beams, d20 mod applies to each attack’s d20; Damage mod in this roller applies once per damage roll. If you need it once per hit, roll each hit’s damage separately.
  

Examples:

• Stealth check +3 → d20 result 14 + 3 = 17.
  
• Longbow attack: d20 mod +7 to hit; damage usually +4 DEX → shows 1d8 + 4.
  
• Greatsword 2d6, STR +4 → normal: 2d6 +4; crit: 4d6 +4 (mod not doubled).
  
• Rapier 1d8 + Sneak Attack 3d6, DEX +3 → crit: 2d8 + 6d6 + 3.

Negative Modifier Example:

• Quarterstaff 1d6, STR −1 → normal: 1d6 − 1; crit: 2d6 − 1 (mod not doubled).

Enter a target DC/AC. For each kept d20, we add your d20 mod and compare to that number. We show Success/Fail in the summary (and optional badges on the d20 cards).

Example: Kept 14 with +7 vs AC 16 → 21 ≥ 16 → Success.

Presets let you save your usual roll setup so you don’t have to re-enter it every time (e.g., “Shortsword”).

1. Set your damage dice (non-d20) and your modifiers (d20 to-hit bonus and damage bonus).
   
2. Type a name and click Save.
   
3. Later, pick the preset from the menu and click Apply, then press Roll Now.
   

>>What a preset saves (stable stuff):

• Damage dice (d4/d6/d8/d10/d12 quantities)
  
• d20 to-hit modifier
  
• Damage modifier
  

What a preset doesn’t save (situational):

• Advantage/Disadvantage
  
• Critical toggle
  
• DC/AC and “Show pass/fail”
  
• Mitigation (Half/Resist/Vuln)
  
• “Totals only” display
  
• d20 quantity (attacks are usually rolled on the spot)
  

>>Where are my presets stored?

They’re saved locally in your browser (no account, no server). Clearing site data, switching devices/browsers, or using private/incognito mode means they won’t be there.

>>Can I edit or delete a preset?

Yes. Save again with the same name to overwrite, or use Delete to remove it.

>>Do presets auto-roll?

No. Applying a preset fills in the fields; you still press Roll Now so you can set situational options (like Advantage or Crit) each time.

Swap to "Urge Mode" which has a die that you can set to take inputs up to 100 :).

Otherwise, you can roll two D10s - but Urge Mode is more fun!

Copies a clean text summary for Discord/VTT/notes.

Example output:

Roll: 1d10 + 2d8 + 1d20
d10: [8]
d8: [7, 3]
d20: [10]
Grand total: 28
Damage: 18

Each dice icon in the "Tools & Display" section will swap your rolled dice to one of our handmade sets from our store! These are lightbox photos of an actual set that we took - so you can try out our dice sets before buying one!

The final option is essentially a "blank" option for if you do not want to use any images when rolling. This is the fastest and most mobile-friendly option that still generates a graphic - if you want pure speed, use "Totals Only" mode.

Check them out here: Handmade Dice – Copycats Store

Hides individual dice cards and shows a Grand total plus per-die totals. Implemented primarily for big pools or mobile users.

Example: Fireball 8d6 → shows d6: 30 and Grand total: 30 without eight separate cards.

Urge Mode is a single die version of the dice roller based on one I quickly coded and used in our Baldur's Gate 3 playthrough on YouTube - this playthrough featured and introduced Urge, a randomized drow who dice rolled for all of his choices.

Over time we got a ton of requests for me to publish my dice roller, but I was always hesitant because it was literally junk I vibe coded in an evening that I didn't think was worthy of a release LOL. This is my answer + gift to the people who watched our series for so long and just wanted to roll like our boy Urge.

Urge Mode is useful if you just need a D20 or even just a random dice roller that can take inputs from 1-100 for everyday use, especially for mobile users running a small game with friends.

Check out Urge at the link below!

Copycats Full Urge Playthrough