Abstract
Massively multiplayer online games (MMOGs) increasingly depend on team collaboration and social interaction, yet most heuristic evaluation of playability (HEP) methods focus on individual player experience and overlook team processes. This study proposes HETP (Heuristic Evaluation of Team Playability), a framework that extends traditional game usability (GU) and gameplay (GP) dimensions by incorporating team collaboration (TCO) and social interaction (SI). HETP was operationalized into a practical heuristic instrument through an expert-driven, audit-based development process. To provide preliminary empirical support, we conducted a controlled comparison with Paavilainen-HEP using the same MMOG prototype, tasks, and interface conditions. Evaluation outcomes were assessed using item-level content validity indices, chance-corrected agreement, and rank-based consistency measures. Results indicated that HETP achieved higher relevance ratings and more consistent expert judgments, particularly in TCO and SI. Overall, HETP provides a reusable, low-overhead tool for evaluating team-oriented playability and supporting iterative MMOG design.