Plausibility of the cloning scenario

Clearly central to the plot of this film are Sam’s clones. They appear not only to look and behave similarly (although there may be one or two hints that they aren’t absolutely identical) but also share a core memory set, although again there may be hints that these aren’t identical (e.g. a moment of hesitation about his daughter).

Memory manipulation in Moon

The big reveal at the midpoint of the film ‘Moon’ is that Sam is some sort of clone, one in a series of clones that are activated, do their jobs and wear down before being ‘disposed of’, at which point the next clone is activated to take over, and on it goes. The intrigue occurs when a clone is activated when one clone is activated while the previous one is still active, and this revealing the whole set-up to both of them.