Different types of visual information overlays are increasingly used in different live streamed contexts to help convey key information and statistics. In the tabletop role playing game live stream scene, overlays have been commonly used for multiple years, however, their impact on viewer engagement remains unclear. 

25 participants watched a 15-minute actual play Dungeons and Dragons clip under one of three conditions: a high-density overlay, a low-density overlay, or no overlay. Engagement was measured with the Narrative Engagement Scale (NES), yielding an overall score and four facets: Narrative Understanding, Attentional Focus, Narrative Presence, and Emotional Engagement. Objective comprehension was assessed via objective questions on game details. The usability was also evaluated among overlay viewers.

Results from the user testing showed a significant increase in engagement when it comes to narrative understanding of the content, and a non-significant increase in general engagement as measured by the NES, but with a moderate effect size (η² = .174). Post-hoc tests of narrative engagement showed that both of the tested overlays significantly improved compared to the control group, but did not produce a significant difference between the two overlay versions. The perceived usability of the overlay was significantly higher in the low‐density condition than in the high‐density condition in terms of clarity, ease of use, and lower levels of distraction.

The findings suggest that overlays do greatly enhance narrative comprehension engagement for viewers. However, adding excessive detail offers no further benefit and may instead hinder clarity and distract the viewers from the video content. Future research should further investigate the effects of longer form content and how different types of visualizations and overlays can provide different effects on viewers' engagement.