Traditionally, the coaster cars are pulled up the first hill by a chain; as the cars climb, they gain potential energy. At the top of the hill, the cars have a great deal of gravitational potential energy, equal to the cars' weight multiplied by the height of the hill.

Most traditional rollercoasters are pulled to the top of the initial "lift hill" by a chain lift system, which operates much like a giant bicycle chain. As the coaster train leaves the station, a "chain dog" (a sturdy metal hook) underneath the car engages with the moving chain, which is powered by a high-torque electric motor at the top of the hill. For a high-value technical detail, modern coasters often feature "anti-rollback" dogs that make the iconic "clack-clack-clack" sound; these are safety ratchets that prevent the train from sliding backward if the chain breaks. While chain lifts are the industry standard, some newer "high-velocity" coasters in 2026 use cable lifts (found on rides like Millennium Force) for a faster ascent, or magnetic launch systems (LSM) that use electromagnetic pulses to propel the train up or through the track without any physical contact. Regardless of the method, the goal is to provide the train with enough potential energy at the highest point to complete the rest of its gravity-driven journey through loops and turns.