Questions and answers about the National Football League players strike:

Q -- What do the players want?

A -- The players have asked for 50 percent of the league's television income, plus other substantial payments, totaling $1.6 billion over four years. The players retained provisions for wage scales and a trust fund from which salaries, incentive bonuses and playoff shares would be paid. Also, players would become free agents after three years. Salaries would be paid from a central fund administered by a trustee.

Q -- What have the owners offered?

A -- The league's last offer, on Sept. 8, would have cost the 28 NFL teams $1.6 billion, over five years, according to Jack Donlan, executive director of the Management Council. This proposal would have given the players immediate bonuses based on years played, increased benefits and, according to most neutral observers, generally maintained the status quo in free agency.

Q -- How does football's free agent system compare with those of other professional sports?

A -- Football now has the most restrictive player-movement requirements of any major sport. Players become free agents when their contracts expire. A team that signs a free agent for $80,000 must give up a first-round draft choice. Higher contracts require more compensation. Only one player ever has changed teams that way -- Norm Thompson, a defensive back who played out his option with the St. Louis Cardinals and signed with the Baltimore Colts in the 1970s.

In baseball, a player with six years experience can become a free agent at the expiration of his contract. All clubs participate in a complicated player-pool system or forfeit the right to choose free agents. Teams losing a quality player are allowed to select a player from the pool (of other than top-line players) as compensation and the team losing a player from the pool receives $150,000 from a fund to which all clubs must contribute.

In the National Basketball Association, there is a right of first refusal concerning free agents. The free agent can accept one offer from a new team and present that offer to his old team. His old team then has 15 days to match the offer and keep the player or work out a trade for him, or match the offer and trade him. If the old team doesn't match the offer or work out a trade, it loses the player and gets no compensation.

In the National Hockey League, free agents can accept offers after July 1. They also present offer sheets to their old team. That team can then match the offer to keep the player or trade him. If it cannot match the offer, the two teams must agree upon compensation, usually draft choices or players. If they cannot agree, the case goes to arbitration.

Q -- Once the strike ends, how long would it take to get a team ready to play again?

A -- The longer the strike lasts, the more difficult it becomes to come back quickly. If the strike is settled by this weekend, the players would have no difficulty beginning play the following weekend. Says Gil Brandt of the Cowboys, "As the strike goes on, the players have a tendency to become disenchanted with working out and maintaining the fitness they had attained. All of a sudden, they're not conditioned for a game. They miss that contact, and if you're out of shape, you become more susceptible to injuries."

Q -- Does the league have a plan on playing the rest of the schedule once the strike ends.

A -- None has been announced.

Q -- Could the league play with nonunion players and nonstriking veterans?

A -- Possibly, but that seems unlikely. A number of coaches have said they would prefer not to field that sort of team. Redskins General Manager Bobby Beathard estimated it would take at least three to four weeks of intense practice to get a team ready to play.

Q -- Do the clubs have a responsibility to pay players injured in NFL Player Association-sponsored all-star games.

A -- The owners say the all-star games are illegal and will go to court to stop them from being played. They say they would not be liable for injuries to players incurred in those games.

Q -- When and where will the all-star games be played, and where can tickets be purchased?

A -- Eighteen games are planned, with six already scheduled. They are scheduled Oct. 11 in Washington (RFK Stadium); Oct. 17 in Detroit; Oct. 18 in Houston; Oct. 31 in Dallas; Nov. 15 in Orlando, Fla., and Nov. 22 in Shreveport, La. The union has not yet announced a ticket price or distribution plan. The games would be televised by Turner Broadcasting System and syndicated to local markets.

Q -- Will the NFL strike go to mediation?

A -- The Management Council wants mediation, the players association says it does not. Ken McMurray, head of the Federal Mediation and Conciliation Service, says he is available and has been in regular contact with both sides.

Q -- Are negotiations scheduled?

A -- No.