It actually happened. The implications of both the players' lawsuit and the owners' lockout are well covered by PFT, The Volokh Conspiracy and The Sports Law Professor Blog.
While there may be no football for awhile, custody, child support and divorce cases continue. Heck, the players have nothing better to do right now, might as well get those cases moving. There are two types of cases, those that are currently litigated and those which have been litigated and the player may want a modification. There are different things to consider in each type. Let's examine them.
In litigation: As always the court will be looking at the "best interest of the child." Is an unemployed dad, the best custodial parent right now? Dad won't be going to offseason lockouts, he won't be traveling for games during the season, etc. If Mom does work, maybe living with Dad is the best to avoid putting the child in daycare. If Mom doesn't work, as Mom has been providing the majority of care because of Dad's work schedule, should she retain custody?
This all assumes that Dad is too involved in being a football player to care for the children. It is a vast generalizations, that is certainly not true individual cases. Football player dads can be just as involved in their kid's lives as any other Dad. But, there unique work schedules and incredible amounts of travel have to be considered. With a work stoppage, all that changes to just any other out of work Dad. If the judge believes the work stoppage may continue for awhile, he may award custody to dad. Or he may decide Mom is the best as the most stable parent all along, looking at the long term. Judges know this lockout won't last forever. They have to make the best decision for the children, not just today and the future. But, if I represented Dad, I would be arguing the current situation that we have today.
Already Litigated: Judges probably won't accept a work stoppage that is mostly likely temporary as a "material change in circumstances" such that moving the children around is warranted. In joint custody situations, Dad can probably get a few more nights. In sole custody situations, hey, it's a great time to spend more time with your kids. Get a weekend overnight that you couldn't have during the season because you worked weekends. See if Mom lets you have the kids for a week (as long as they get to school). Taking a trip is probably not a good idea since you don't know when your next paycheck will be. There are lots of free or low cost things you can do with your kids though. Time to do those things you would promised you would do "when you had the time." Time is all you have now. No offseason workouts with your teammates at the team facilities, no OTAs, maybe no training camp. Take advantage of the downtime to hang with your kids. Even if you never missed a visitation, try to spend some extra time with the kids. They will love you forever for it.
In Litigation: Again, depends on how the judge sees it. If the judge knows this is temporary, he may look at the player's contract and based alimony on that income. This is the most likely scenario. No player is ever guaranteed a spot on a team and a continue paycheck (Not even Tom Brady and Peyton Manning. Believe me if they had not come back from their knee surgeries as well as they did, they would have been cut). The only thing guaranteed to a player is the guaranteed money stated in the contract. Given that reality, a temporary work stoppage has no more effect on a player's income that being waived by a team. A judge has to look at the income and make a decision about the player's future ability to make payments. On the other hand, the judge could look just at current income ( 0 ) and know that the player could be cut when -- and if -- training camps ever open again. The judge could then say the player is not voluntary impoverished since the owners locked him out of his employment. He could then look at the player's ability to get another job and what that job would pay. The decision about alimony would be based on that likelihood of getting employment.
Already Litigated: The player could really be screwed here. In some states (like Maryland), alimony is not modifiable. What was established when the divorce was litigated is what the player is stuck paying, regardless of financial situation. The good news is that alimony is not the lifetime pension it is was once. In the 21st century, the wife is expected to get off her butt and get a job. Just because she was married to a rich football player once up a time does not negate her need to be self-supporting.
In Litigation: Much the same analysis as alimony. With one huge exception -- you are expected to sacrifice and do what you can to support your children. Supporting your ex-wife, not so much sacrifice expected. A player would be expected to get a job during the work stoppage to make sure his kids have food on the table, a roof over their heads and clothes on their backs. The judge may figure child support based on the player's football income, presuming the stoppage will be temporary. Temporary unemployment will not relieve one of the obligation to pay child support. The judge may consider the temporary job in assigning a temporary amount to be increased when the player returns to the playing field.
Already Litigated: The standard for a change in child support payments is the same as for a change in custody -- "material change in circumstances." It is up to a judge to decide whether a most likely temporary work stoppage is enough to warrant a permanent change in payment amount. This is unlikely. Whether dad is working or not, the kids still need to be supported. The amount won't likely change. The judge could decide to temporarily suspend payments until the player returns to the field. The player would then be responsible for all the back payments. This is unlikely though. The lockout should not impose a hardship on the children who had no say in whether it occurred or not. The children cannot make up the difference of the child support payments. Dads need to continue making these payments, whatever other sacrifices they make during the lockout.
Obviously, the players should have been saving their money for just this situation. They should have enough money saved to meet all their financial obligations until the paycheck resumes. Some will have done so. For those players and their families, life will go on just as before. For those that didn't, they may be explaining their lack of financial responsibility to a judge. It will not be pretty. I don't see any judge being particularly sympathetic to someone who makes more at the League minimum than most people make not saving some of that money for the lean times.
We all hope this Lockout is temporary and we have football come fall. For the players facing family law issues, this just complicates an already difficult time. Resolving it quickly will mean one less uncertainty to deal with in court.