Real answer: rolling isn't the weak link, everything AFTER the roll is. Four ways 100 real rolls still end up compromised: 1) die bias — cheap dice aren't uniform, so your rolls lean toward certain faces, quietly cutting entropy below 256 bits. 2) miscounting rolls-to-bits during the base6-to-binary conversion. 3) off-by-one on the BIP39 wordlist index — silently gives you a DIFFERENT valid seed, no error thrown. 4) piping the conversion through some random tool instead of doing the math by hand. The dice were fine. The pipeline wasn't.