For players to be traded under the NBA's most recent collective bargaining agreement, the aggregate of salary must be within 125 percent of each other plus an additional $100,000.
The complexity of this rule is what led to the creation of RealGM's Trade Checker.
The players want the percentage to rise to 225 percent until the NBA's next CBA. The owners have indicated a willingness to increase the percentage to 140 or 150 percent.
Teams paying the luxury tax would have a tighter restraint.
Under the current system, teams that are under the cap can use their space to absorb salary that goes beyond the 125 percent.