The ground should be relatively level; however, there are several features on the unit that can be adjusted to accommodate a minimal grade. Rainbow Play Systems is the only company to offer extended ladders and "A"-frame legs to allow for installation on a slope. Also, several components have built-in adjustable features. The best way to accommodate an un-level yard is by installing safety surfacing before your play system arrives. This way, not only are you protecting your child from a potentially harmful fall but also eliminating the un-level yard issue. If you have a question about your yard, please ask a member of our sales staff for assistance.