We describe steps and means required to present and solve problems of the class of Reproducible Game Trees by means of the package RGT Solver. Namely, given specification of RGT problems and perspective strategy related knowledge RGT Solver by PPIT algorithms elaborates and tests plans, selects the best actions for the given plan and processes them. We prove the validity of PPIT by successful experiments in elaboration of endgame strategies for chess RGT model problem and provide an evidence of validity of PPIT for known Retie etude.