ThinkGeek has created an amusing set of LED dice (specifically a d10, d12, and d20) that light up when they roll a critical hit–meaning that the d10 lights up when it rolls a 10 and so on. Previously, ThinkGeek had only produced a d20 die in this style.
Each set comes with a d10, d12, and d20, which all flash red when their highest number is rolled. Now, we’ve done everything in our powers to ensure these dice are weighted as evenly as possible considering the electronics inside. We did this because we’re gamers and we really wanted to use them ourselves and cheating sucks.