What this tool does
Two classic randomizers in one page. The coin flip animates, lands on heads or tails, and keeps a running tally of your session. The dice roller throws 1 to 6 dice of any standard tabletop size (d4, d6, d8, d10, d12, d20), shows each die, totals them, and logs every roll in a history list.
How the randomness works
Both tools draw from crypto.getRandomValues, the browser's cryptographic random generator. The coin is a single fair bit (50/50); each die is a uniform draw from 1 to its number of sides, using rejection sampling so no face is favored. Rolls are independent: the dice have no memory of previous results.
Worked example
Rolling 2d6 (two six-sided dice) gives faces like 4 and 2, for a total of 6. The most common total on 2d6 is 7, which comes up about 1 time in 6, because six of the 36 combinations make it.
Tabletop uses
The d20 is the classic Dungeons and Dragons die for attacks and checks; d4, d8, d10 and d12 cover most weapon and spell damage. Rolling several dice at once with the total shown matches how damage rolls work at the table.
Limitations
The history keeps your last 20 rolls on this page only; it resets when you reload. For games that need witnessed or certified randomness, use physical dice or a regulated system.