Uncanny Valley in Video Games: An Overview

Dawid Ratajczyk's review examines the uncanny valley hypothesis, originally proposed by Masahiro Mori in 1970, and its application to video game characters. The paper argues that as rendering technology advances, highly realistic but imperfect human characters may provoke eeriness rather than engagement, and that it remains unclear whether rising computational power alone will resolve this problem. The central conclusion is that researchers must first identify which character attributes trigger the effect before developers can reliably avoid it.

The review surveys empirical work on the topic, including studies of motion-captured and CGI characters that rated human-likeness, familiarity, and attractiveness. Findings generally support a non-monotonic relationship between realism and likability, with some studies identifying multiple uncanny dips. Competing explanations are considered, notably the perceptual mismatch hypothesis, which attributes discomfort to inconsistent sensory cues, and theory of mind accounts, which emphasize difficulties reading facial expressions and eye movements. The eyes and facial regions emerge as especially important, and the author notes that realism of inanimate environments does not appear to trigger the effect.

The paper's scope is primarily academic literature from 2004 to 2018, supplemented by public commentary from players and reviewers on titles such as Grand Theft Auto IV and Mass Effect: Andromeda. Its methodology is a narrative literature review rather than original data collection, so its conclusions depend on the consistency of the cited studies, which the author acknowledges is limited.

Stylisation is presented as a practical alternative to chasing photorealism, being cheaper to produce and frequently preferred by audiences. The review also observes that the uncanny effect can be used deliberately, as with repulsive characters or in games where it arguably enhances the experience. Overall, the work concludes that fully convincing realistic characters in games may be distant, and that the economic stakes for developers are substantial.