For those of you not in the know, there is a discussion among certain OSR bloggers who care about player agency involving the concept of a “quantum ogre”. The quantum ogre refers to a form of negation of player agency where, if the characters make choices that would allow them to avoid an encounter, the encounter is moved in time or space so that the characters encounter it anyway. The ogre is encountered despite the choices of the players.
“Quantum ogre”, which I believe is a reference to Schrodinger’s cat, is actually a misnomer. It implies some randomness or uncertainty regarding the ogre, whereas the ogre is actually characterized by its certainty. In contrast to Schrodinger’s cat, its existence is certain. Moreover, its existence in time and space is also determinable by its proximity to the PCs. It is a “deterministic ogre”.
An ogre on a random monster table, by contrast, does not have a guaranteed existence. Until the random monster check, or hazard die check, neither players nor GM know whether the monster exists. It is “Schrodinger’s ogre”.
Unless it also appears as a keyed entry – it is a “wandering monster” as opposed to a “random monster”. In that case, the existence of the monster is certain, but it location, or rather its movement, is uncertain. Call this a “Brownian ogre”.
In contrast to the quantum (deterministic) ogre, the Schrodinger’s and Brownian ogres preserve player agency, because the check is triggered by choices of the players (resulting in either character action or inaction).