A successful major connector in a removable partial denture must be rigid to ensure even distribution of occlusal forces across the abutment teeth and edentulous areas. Rigidity prevents torquing and flexing of the prosthesis, which can cause tissue irritation, bone resorption, and damage to the abutment teeth. A flexible or compressible connector leads to instability and reduces the support and retention of the denture. Additionally, rigidity maintains the functional integrity of the partial denture during mastication and enhances patient comfort.

Reference: Prosthodontics, Zarb & Bolender, 13th Edition.