To shaft someone means to treat them unfairly or to cheat them.
Being shafted is a bad thing. It can make people feel sad or angry.
Examples:
He shafted me out of my lunch money.
She felt shafted when she didn't get a turn.
I don't want to be shafted out of my prize.
I got shafted by the bad man!
He always gets shafted in games.
She shafted me and took my toy.