What is the ethical responsibility of game designers, and why does monetising players conflict with duty ethics?

Commercial success requires holding the player's attention for as long as possible, but designers must also consider their product's effects on players. Using players merely as a means to profit contradicts duty ethics, which forbids treating people only as means.

The commercial pressure: revenue depends on attention, so the game has to appeal to a large audience, stand out from competitors and keep players engaged.

The ethical demand: the developer must weigh the product's impact on users. In Kantian duty ethics (deontology), people must never be treated merely as a means to an end. A design that treats players as attention to be harvested for profit violates that principle.

What ethical game architecture can look like: it goes beyond depicting ethical themes in the content and reaches into the game mechanics themselves:

• feedback mechanisms and incentives that encourage moderate play times,
• making the usually opaque and seductive mechanics transparent, so players can "pursue the options that serve them better".

Tip: players being happier or having more fun does not prove the design is good. Fun can be engineered by exactly the mechanisms that harm them.

Go deeper:

• Wikipedia: Categorical imperative — Kant's formula of humanity: never treat people merely as means.