All children under 12 years old must be accompanied by an adult of 18 years and above. Children under 3 years old can visit the park for free. The following height and age restrictions apply: Guests must be 1.4m or over to ride Nemesis, Galatica, The Smiler, Oblivion and Rita (Rita has a maximum height of 1.95m).

Whether a 10-year-old can ride The Smiler at Alton Towers in 2026 depends entirely on their height, not their age. The ride has a strict minimum height requirement of 1.4 meters (approximately 4'7"). Because The Smiler is a high-intensity "infinity coaster" with a world-record 14 inversions and significant G-forces, the restraint system is designed for bodies of a certain size to ensure safety. Most 10-year-olds in the UK and US average around 1.35 to 1.45 meters, so many will be just tall enough to ride. However, parents should also consider the child's emotional maturity, as the ride's "Marmaliser" theme is designed to be intentionally disorienting and intense. If the child meets the 1.4m mark, they are legally permitted to ride, but a final "test seat" is usually available at the entrance to ensure a comfortable and secure fit.