Researchers at the Norwegian University of Science and Technology (NTNU) have found that humanoid robots can serve as engaging playmates in physical games, although user enjoyment depends heavily on how naturally the robot behaves during interactions. The study examined how people responded to playing a physical game with Pepper, a humanoid social robot designed to interact with humans. Researchers conducted a controlled laboratory experiment in which participants played a version of trash can basketball, throwing crumpled paper balls toward a target alongside or against the robot.
The research explored two gameplay formats: cooperative play, in which participants and Pepper formed a team, and competitive play, in which they competed against one another. Researchers also varied the order of play, with either the human participant or the robot taking the first turn.
According to the findings, participants reported the highest levels of enjoyment when games began in cooperative mode. Competitive play also generated positive responses in some cases, particularly when participants started the game themselves. Those participants often described competition as more exciting and motivating because it provided a clearer sense of control and challenge.
The study found that defeating the robot created a sense of accomplishment for many participants. Some reported particular satisfaction when Pepper missed its shots, suggesting that competition with a robot can produce emotional responses similar to those experienced in human-versus-human games.
At the same time, the research identified several factors that reduced enjoyment. Participants frequently became frustrated when Pepper’s movements appeared stiff, when it paused for long periods before taking a turn, or when its behavior seemed excessively focused on winning. Frustration was especially pronounced when the robot initiated games in competitive mode.
Yavuz Inal, an associate professor in NTNU’s Department of Design in Gjøvik, said the results indicate that robots can function as playmates when their actions match human expectations. He noted that factors such as gameplay mode, pacing, player roles and turn order influence whether interactions are perceived as enjoyable or frustrating.
The researchers argue that humanoid robots create higher expectations because their human-like appearance and behavior encourage people to anticipate human-like social skills. When those expectations are not met, users may react negatively even if the robot performs its intended functions.
The findings contribute to ongoing research into social robots and suggest that future systems designed for recreation, exercise and other everyday activities may need to place greater emphasis on responsiveness, timing and natural interaction patterns in order to maintain user engagement.
Photo credit: Suraj De, NTNU
