Six Flags of Texas now requires chaperones for kids under 15 after 4pm.

Six Flags Over Texas now requires children under 15 to be chaperoned by someone over 21 after 4pm.

Why it matters: Six Flags joins the State Fair of Texas in requiring most minors be accompanied by an adult in the evening.

• The Arlington-based theme park operator said the policy aims to ensure that "all guests have the best time ever and leave happy and eager to visit again."

The big picture: Six Flags, like other amusement parks, have seen a decline in attendance .

• The park attributed the policy change to an increasing number of incidents involving "unruly and inappropriate behavior at amusement parks and other major entertainment venues."

How it works: A chaperone must have a valid government-issued photo ID confirming they are over 21 to accompany youth under 15.

• Any unaccompanied minors in the park after 4pm will be asked to leave.
• Chaperones must be with the kids when they arrive, remain at the park throughout the visit and be reachable by phone.
• An adult can accompany up to 10 kids 15 and younger.

What's next: The Six Flags in Arlington is hosting an Oktoberfest Food Festival every weekend through Nov. 3.

• Fright Fest starts Friday the 13th. This year's theme honors the 20th anniversary of " Saw ."
• The kid-friendly Boo Fest starts Saturday.