I know “fair marriage” is an oxymoron, but here's what it would look like: 1. It's an equal partnership. Both husband and wife work. 2. All money is the property of the person who earned it. Therefore, they keep separate bank accounts, separate checking and separate savings. 3. They share expenses equally, going halfsies on the electric, Internet, etc. Each person pays their own cell phone bill. 4. In the event of kids, they have a choice to make. Either one partner stays home with the kids while the other earns all the money or, after a brief maternity leave, they both keep working and they split the cost of day care. In the event they choose the former, the person earning all the money has authority over the household.
5. In the event of a divorce, they go their separate ways and continue earning their own money. Neither owes the other alimony. 6. In the event of a divorce where kids are present, they will continue to split the cost of raising the kids. Child support will be based on the kids needs and will not go up higher than their needs are. In other words, no million dollar child support just because dad makes millions. Child support is for providing things like diapers and food. It's not for luxury. 7. In the event of a divorce, the court will not be biased toward either party. It shall determine custody based on the best interests of the child/children. 8. In the event of a divorce in which they own a house together, they will do one of two things. 1. Sell the house and split the proceeds half/half. 2. Choose one party to stay in the house and that party will owe fair market value rent to the other person. If rent is not paid for more than 2 months, the person living there will be evicted and they'll sell the house. 9. In the event of a divorce where one party is not gainfully employed, that person will be expected to get a job and self-support after the divorce. 10. A person's inheritance is off limits in any divorce.

^{^} I know the above isn't even remotely the reality, but that's my best shot at making marriage/divorce actually be fair or at least resemble fairness. Feel free to add anything I missed.