Objects are replicated in order to increase reliability and availability of an object-based system.We discuss how to invoke methods on replicas of objects in a nested manner. If a method t is invoked on multiple replicas and eachinstance of t on the replicas invokes a method u on another object y, u may be performed multiple times on some replica of y and then the replica gets inconsistent, i.e. redundant invocations. In addition, if eachinstance of t issues a request to a quorum, more number of the replicas are manipulated than the quorum number of the method u, i.e. quorum explosion.We discuss an invocation protocol to resolve the redundant invocation and quorum explosion. We evaluate the protocol on how many replicas are manipulated and requests are issued.