This RNG utilizes the cryptographically secure browser API methods found in the window.crypto object. It additionally uses Winkler, an open source library for generating client-side entropy by measuring fluctuations in the machine's state. It intends to produce a mathematically random sequence suitable enough for encryption.
This is a simple dice roller for use with tabletop games. It is also a demonstration of different random number generators (RNGs) and various algorithmic techniques used to achieve as close to mathematical randomness as possible, using a computer. This is not a straightforward task, and is studied well in the field of cryptography - its application ever crucial in the fast-paced world of cybersecurity.
This weird foray into cryptographically sound dice stemmed from real-world frustration with physical DnD dice. I created an open-sourced clojure(script) library called Winkler as a solution for client-side entropy generation, and wrote more thoughts about it here. Sure, maybe a demonstration with dice is overkill, but would you trust your character's fate to anything less than the power of chaotic indifference that is a truly random dice roll? I think not.