Misaligned dies, usually abbreviated MAD :headbang:, are somewhat common, but many beginners mistake these error coins for the less common true off center coin. This post is intended to be a reference for you, a detailed guide you can refer to when people ask questions. :loud: These somewhat common errors occur when the hammer die is off centered, but the coin sits correctly in the chamber. The anvil die strikes a normal strike (centered), but the hammer die comes down off-centered. This is especially common on dimes, for some reason. The unusual affect is that only one side of the coin is off centered. On US coins, this is usually the obverse. There is also vertical misalignment, where the hammer die is tilted such that one side of the dies comes together closer (and thus has a stronger strike than) the other side of the die. I recently saw a three center that exhibited this less common misalignment. Misaligned die errors are not worth much of a premium, although in extreme cases they are worth something. They don't really have much value until parts of the design are missing - most MADs are so small that the entire design is still present, but the rim is noticeably thicker on one side. I have sold a couple of MAD quarters on Ebay for $1 each. An interesting effect of a MAD is that while the misaligned side will be fully struck, the centered side usually has weak details opposite the off-centered portion of the coin. You can see this particularly well on the quarter I will post. I have several MADs, but these are my three best examples. As I mentioned, dimes are the most common coin to find misaligned. The small size of the dime and cent is a contributing factor in the plentitude of MAD's on these coins. Nickels are the second most common, although my nickel is further off-centered than most. The design is cut off at the bottom left, albeit slightly. The quarter shows the weakness on the reverse opposite the off-centered portion of the obverse, even though it is centered.