Going Quantum Without Context: Not Every Game Is a Prisoner’s Dilemma

Quantum information theory gives us powerful tools like the Eisert–Wilkens–Lewenstein (EWL) game quantization protocol, which can resolve classic dilemmas using entanglement. But not every problem is structured like a dilemma. In this post, I examine an attempt to apply EWL to a continuous supply-chain game—and why that move misses the mark. The lesson is clear: when the structure does not fit, quantum form becomes cosmetic and brings no real value. As always, context is everything.

Faisal Shah Khan, PhD

6/28/20253 min read

Quantum game theory offers one of the more surprising intersections between information, strategy, and quantum mechanics. Through the work of Eisert, Wilkens, and Lewenstein in "Quantum games and quantum strategies," we learn that quantum entanglement can reshape the very landscape of strategic interaction—permitting equilibria once considered unreachable. In the Prisoner’s Dilemma, a simultaneous move game and a paradigm of individually rational behavior producing a socially suboptimal outcome, entanglement breaks this dilemma and leads to a socially optimal result. This is not science fiction, but a direct consequence of the geometry of the underlying state space—and something that has already been tested on contemporary quantum computers.

Yet like any formalism, EWL comes with conditions. It is grounded in discrete two-player, two-strategy games with a specific kind of payoff structure—one that exhibits a strong imbalance in the off-diagonal outcomes. In such games, if Player A chooses one strategy and Player B chooses the opposite, Player A might receive a high payoff while Player B receives nothing—for example, a payoff pair of (5 for A, 0 for B). If the choices are reversed, so too are the payoffs: now B receives 5 and A receives 0. These kinds of outcomes create a conflict: each player wants to be in the position that yields the higher reward, but only one can succeed. This competitive asymmetry, where optimal outcomes are mutually exclusive, is precisely the kind of strategic scenario that quantum entanglement is designed to address within the EWL framework. (For some context on how EWL quantization resolves such dilemmas, readers may refer to my earlier post: Beyond Classical Mediation: Enter the Quantum Referee.)

EWL was never meant to be a plug-and-play protocol for arbitrary strategic settings. And yet, that is exactly how it is used in the 2022 paper "Quantum game approach for capacity allocation decisions under strategic reasoning," which applies the EWL scheme to a classical capacity allocation game in supply chain management.

The Jump from Discrete to Continuous

At first glance, the ambition is admirable. The authors seek to elevate a continuous economic game—where two buyers compete for limited supplier capacity—into the quantum domain. They invoke the circuit for the EWL quantization protocol, describe entanglement parameters, and report equilibrium improvements. However, the careful reader is left searching for the underlying game-theoretic scaffold that justifies such an extension.

The original strategies in their model are continuous, not discrete. Although the authors remind readers that the EWL protocol collapses to the classical game in the absence of entanglement, they do not demonstrate this for their particular case. It is true that EWL reproduces the classical game—but that game is specifically the Prisoner’s Dilemma, or a close relative such as Chicken (or any member of the Hawk–Dove game family). In those cases, a well-defined 2×2 payoff matrix underlies the entire construction. This model lacks such a matrix. More crucially, it seems to lack the off-diagonal payoff asymmetry that makes the EWL transformation nontrivial.

What remains is the language of EWL without the logic of its construction.

A Formalism Misapplied And Why It Matters

This is not to say that the idea is unworthy. It is possible that introducing entanglement into their model reveals new and interesting dynamics. However, those dynamics are not clearly attributable to the EWL protocol, nor are they shown to arise from a consistent transformation of a classical game into a quantum one. The authors assume what they must demonstrate: that the system they construct supports the very kind of quantum Nash equilibrium the EWL formalism was designed to uncover.

There is a broader lesson here. Quantum formalism is not a universal solvent. Its power lies not only in superposition and entanglement, but in the precise mathematical architecture that makes those features consequential. When that architecture is missing, the results—however elegant they may appear—risk becoming decorative: quantum in form, but not in function.

In fields as diverse as economics, cognition, and now logistics, we are beginning to recognize the potential of quantum models. However, if we are to take these possibilities seriously, we must apply them with the same mathematical discipline that made them powerful in the first place. Not every coordination problem is a Prisoner’s Dilemma. And not every strategic interaction can be rescued by entanglement.