You've filled out your ballot. You've carefully selected your candidates. You've even managed not to spill your drink on it.
Congratulations. You're already ahead of some voters.
Most paper-ballot scanners work by detecting marks in specific locations. They're very good at following instructions, but not particularly good at interpreting artistic expression.
Circle a candidate's name instead of filling in the oval? The scanner might not recognize your choice.
Accidentally mark two candidates in a race where you're supposed to pick one? That's called an overvote, and the scanner may flag it for review.
Then there are the ballots that arrive wrinkled, torn, stained, or otherwise looking like they've survived an encounter with a hungry raccoon.
So what happens?
In many states, election workers review ballots that can't be scanned. When the voter's choices are clear, authorized workers may carefully transfer those selections onto a fresh ballot the scanner can read.
It's called ballot duplication.
And no, that doesn't mean somebody gets two votes. The original and its replacement are tracked, with only one set of votes counted.
Other jurisdictions use hand counting instead.
The important bit? A scanner rejecting a ballot doesn't automatically mean the vote is lost.
Sometimes democracy just needs a human to explain the paperwork to the machine.