Maximin is a the highest possible safe alternative.
Here are some examples to illustrate. To maximize your happiness you might want to become rich. You could attempt to do this on a number of different levels.
You could rob a gross of banks, buy a small country, build a large military force, and conquer the world. That would be an example of maximaxing your wealth.
Or you could invest all your money in high risk stocks, hoping to make a quick couple million. This would be an attempt to maximize your earnings. It's not insane, but it does involve quite a lot of risk.
Or you could just get a good job and work for a couple decades. This would be maximining your earning potential. Assuming that you can get a good job, you should always earn a good-enough income, and should be safe from loosing all your money or ending in jail. It certainly wont make you make you as rich as it is possible to be, but it will meet all your basic needs and then some. It will satisfice.