Nil preference situations
Free will arises from random selection of alternatives in nil preference situations.
When an otherwise deterministic system makes a random choice in a nil preference situation, that system exhibits free will.
A nil preference situation is one in which an agent must choose between a variety of equally preferred alternatives. For example, whether to eat one orange or another (from a bag of equally good oranges).
The available alternatives may have arisen from deterministic factors but "when the dice roll" the choice is made freely.
The Copeland Argument
"The suggestion I am going to consider is that free choice, in such circumstances, consists in making random selection between equally preferable alternatives. According to this suggestion, your choice is only partly the outcome of determining factors. Such things as your long-standing preferences and the transitory state of your blood sugar level deterministically close off all your options save the choc pud and the cheesecake. The final selection between these two, though, is entirely random. If this view of things is correct, neurophysiological determinism reigns only until the final shortlist of options has been drawn up. Then the dice roll.
I'll use the term nil preference choice for a situation where a selection is made between alternatives that are by and large equally satisfactory, as far as the chooser is able to tell, given the time available for deliberation, and the information at his or her disposal" (J. Copeland, 1993, p. 145).
References
Copeland, Jack. 1993. Artificial Intelligence: A Philosophical Introduction. Blackwell Publishers.