Simplify the following text for a Grade 12 native English-speaking person.
Original: The conditions which Lasker demanded for World Championship matches in the last ten years of his reign were controversial , and prompted attempts , particularly by his successor JosÃ RaÃ l Capablanca , to define agreed rules for championship matches .
Simplified: The conditions which Lasker demanded for World Championship matches in the last ten years of his reign were controversial , and prompted attempts to define rules for championship matches .