The meaning of ‘free’

the meaning of ‘free’

The passage below is from ‘the Blank Slate’ by Steven Pinker.

http://evolbiol.ru/blankslate/blankslate.htm

His lottery began as the familiar game in which a winning ticket was rewarded by a jackpot. But to enhance the suspense the operators added a few numbers that presented the ticket holder with a fine rather than a reward. They then imposed prison sentences on those who did not pay the fines, and the system expanded into a variety of nonmonetary punishments and rewards. The lottery became free, compulsory, omnipotent, and increasingly mysterious. People began to speculate on how it worked and whether it even continued to exist.

In this passage, I’m not sure what the underlined ‘free’ exactly means.

It seems ‘free of charge’ in a sense, but also to be able to mean ‘at liberty’ in another.
I’m in a dilemma.

Hope for your replies.