Use Very Good Dice Roller for your dice rolling needs, or do not. I am not a beggar.
Custom Rollsd
Mersenne Twister
Math.random()
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Randomness Test Configuration
(20-100 available)
No random number generator is perfect, but this test is designed to confirm that yours is performing well enough for everyday dice rolling.
Every die on the roller — d4, d6, d8, d10, d12, d20, and d100 — is rolled 10,000 times per cycle and checked for an even spread. Because each individual die test has a small chance of flagging a failure even with a perfectly healthy random number generator, you'd expect around 30% of cycles to show at least one failure. That's not a problem — it's exactly what's supposed to happen. The test is specifically checking whether your failure rate falls within that expected range. If it does, your random number generator is working correctly.
If the test fails, run it again two or three times. A one-off failure is normal. Only worry if you're seeing consistently high failure rates across multiple runs, or the same die keeps failing every time.
You can run between 20 and 100 cycles — more cycles gives a more reliable verdict but takes longer. Two algorithms are available to test: Mersenne Twister and Math.random(). Mersenne Twister is recommended for both testing and your dice rolls.
Status: Preparing test...
Statistics
Natural shows raw dice values. Add non-natural results to blend in or separate advantage, disadvantage, and modified rolls to your dataset. You can also show the raw dice values of non-natural rolls alongside the raw dice values by including non-natural results and keeping the natural button toggled on.
