Free will
The precondition for the whole thing. Without real choice there is nothing to learn from.
Free will is the load-bearing assumption of the model. Growth happens through choices and their consequences, so the choices have to be genuinely open — otherwise nothing is being learned, only executed.
The material treats free will as inviolable, to the point of saying the larger system will not step in and override you even when it dislikes what you are doing. Which also means nothing is going to rescue you from the consequences.
It notes a limit worth holding onto: the avatar has no free will of its own. It is data in a simulation. The choosing happens at the level of the consciousness driving it.
Where this gets misread
That the absence of intervention means indifference. The model's claim is the opposite — that non-intervention is the only arrangement under which growth is possible at all.