International construction contractors are often faced with the situation of working in an unfamiliar construction environment. Under FIDIC rules, the contractor has the right to make a claim requesting the consulting engineer for an adjustment to the contract price or the time for completion when a part or parts of the works have changed, or in the event of unforeseeable conditions. Contractors generally have more access to the costs and time implications of such a change or unforeseeable conditions than the consulting engineer or outside neutrals. Due to such an asymmetry of information, the contractor may be motivated to dispute frivolous claims of less merit, expecting erroneous judgments by the consulting engineer or the neutrals. In this paper, a claiming behavior model is presented by using game theory and experience data to study the manner in which frivolous claims develop into disputes. The model also analyzes the impacts of DAB/DRB upon the frivolous claims.