If you lock a pair of newborn genetically identical twins into a room where they will share the same environment, they will walk out of that room as two distinct individuals. The source of the unique individuality of one twin will be the entropy (unpredictability) of the behavior of the other and vice versa. Any living creature exports informational entropy into the environment to keep the entropy of its inner model of the world as low as possible. The roaming entropy (exploratory behaviour) of any living creature exports into the environment the informational entropy of the creature’s inner models of the future states of the world.


Yet if the room will not expand, the twins may well end up killing each other.


The digital life of Rebandon will be real in a sense that like in real life it will increase the roaming entropy 1 of its behavior in the environment in order to minimise the informational entropy (free energy) of its model of the world 2 . The increase in the roaming entropy of artificial agents will become a natural source of unexpected uncertainty in Rebandon both for them and for human players. Human players will also increase their roaming entropy as a result 3.

Unexpected uncertainty is a relatively new but already robust scientific concept 4,5,6. It emerged from the necessity to distinguish the role of different types of uncertainty in action, perception, exploration and learning 7,8. Unexpected uncertainty is pertinent to contextual changes in the environment which affect probability ratios of commonly happening uncertain events (expected uncertainty)9. In particular, the importance of unexpected uncertainty for the development of a high level value based (contextualized) decision making ability in adolescence was underlined 10,11. High level dopaminergic rewards for resolving unexpected uncertainty  of the context have been demonstrated to exceed the lower level dopaminergic rewards for positive outcomes in short stimulus-response cycles 12,13,14,15.

The process of resolution of unexpected uncertainty was mathematically presented as a real world application of the free energy principle, the first principle of life coined by the world’s most influential neuroscientist Karl Friston 16. A team lead by the most cited computer scientist in the world Yoshua Bengio recently proposed a model-based deep reinforcement learning method 17 that relied on learning an approximate, factorized transition model to tap the unexpected (contextual) uncertainty of the real world.

Fortnite Battle Royale is the most recent example of a mass culture product that offers uncertainty as the main reward for players 18. Unexpected uncertainty in Fortnite is present as rare exceptions to a typically zero-sum game of battle royale genre 19.

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