🎲 Coin Flip & Dice Roller

About This Tool

This Coin Flip & Dice Roller uses JavaScript's Math.random() function to generate cryptographically-unpredictable pseudo-random numbers. While Math.random() is not suitable for cryptographic security, it produces uniform distributions that are entirely fair for games, decisions, and probability experiments. Each result is statistically independent — past flips have zero influence on future ones.

Coin Flip Features

• Single flip: Animated 3D coin with CSS rotateY spin — clicks and spacebar both trigger a flip.
• Multi-flip: Flip 2, 5, 10, 20, 50, or 100 coins simultaneously and see each result as a mini-coin grid with a Heads/Tails summary.
• Streak tracking: Displays your current consecutive same-side streak with a badge.
• Live stats: Total flips, heads count, tails count, best streak, and a visual ratio bar that fills gold for heads proportion.
• Mini bar chart: Last 20 flips visualized as a bar chart — gold = heads, grey = tails.

Dice Roller Features

• All standard RPG dice: d4, d6, d8, d10, d12, d20, d100 (percentile), plus custom-sided dice up to d1000.
• Multi-dice rolls: Roll up to 20 dice of the same type simultaneously, with individual SVG die visuals.
• Modifier support: Add a positive or negative integer modifier to the total (standard in D&D / Pathfinder).
• Drop Lowest / Drop Highest: The classic D&D stat-generation mechanic — roll 4d6 and drop the lowest for balanced ability scores.
• Exploding dice: When a die shows its maximum value, it is re-rolled and the result added to the total.
• Frequency chart: Bar chart of rolled values across your session, showing distribution trends.

Probability & Math.random()

JavaScript's Math.random() returns a floating-point number in the range [0, 1). To roll a fair d6, the formula is Math.floor(Math.random() * 6) + 1, which maps the continuous [0,1) range onto the integers 1–6 with equal probability of exactly 1/6 each. For a coin flip, any value below 0.5 is heads and any value ≥ 0.5 is tails, giving exactly 50/50 odds over a large number of trials.