For kids only, participating bowling alleys will offer two games of bowling per day for free during the summer. To register, click "Sign Up Now", select your location, and fill out the short form. Eligible dates vary by location, but most run from May to August. Note that shoe rental prices may still apply.
Of note, once you've registered your kid(s), you'll have the option to register for a Family Pass for $28.95. This entitles up to four adults to join their children for those two games per day.