The Birthday Party of No Return — R.L. Stine

Lee Hargrove wishes he could be lucky like his friend Cory Duckworth. Cory has to be the luckiest kid on the planet. Even Laura Groden, the girl Lee has a crush on, prefers to hang out with Cory. All Lee wants in life is to get a scholarship to Summer Sports Camp. But there's only one scholarship from his school and he's competing against Cory and Laura. Then Lee receives a good luck charm in the mail. It's a vulture's claw and Lee's life seems to change immediately. Until bad things start to happen. The vulture's claw is bringing really bad luck. Lee tries to give it to Cory as a birthday present but Cory already has one of his own. When both boys' luck take a turn for the worse, Laura wins the scholarship and admits to sending the bad luck charms to both boys.