Fear is a multifaceted emotion, challenging to define and assess accurately. Biologically, it is an innate response to threats, whereas psychologically, it is shaped by individual experiences and societal influences, sometimes evolving into specific phobias. One such phobia, arachnophobia (the fear of spiders), is particularly widespread and can vary widely in intensity among individuals. This paper presents a prototypal system that classifies the severity of arachnophobia using Machine Learning (ML) algorithms within a Virtual Reality (VR) game-based environment. The proposed system utilizes a two-stage clustering approach to analyze the behavioral data collected during VR exposure. Additionally, participants' self-reported fear levels are measured using the Spider Phobia Questionnaire (SPQ), to provide a comprehensive assessment. Preliminary results suggest that this method could be effectively used to classify arachnophobia intensity level, thus offering potential applications in both clinical settings and video games.

We present a study on stress detection in virtual reality using The Last Secret, a stealth game we developed that integrates advanced multimodal stress detection techniques and in-game behavioral metrics. Our game responds to the player's emotional state and stress levels, dynamically adapting its gameplay in real-time. Players need to manage their stress to navigate the game effectively: maintaining calmness keeps them in an optimal flow state, whereas excessive stress can push them into a frustrating state, making progression significantly more difficult. We present experimental results showing the impact of stress-modulated gameplay on player engagement and performance, revealing findings aligned with the flow theory.

In the realm of video games, achieving a state of flow is paramount for player engagement, striking a delicate balance between boredom and anxiety. Under such circumstances, monitoring player's stress level plays a crucial role. Here, by addressing state-space dynamics, we model stress unfolding over time, allowing for both its continuous and discrete assessment. This study builds upon our previous research, advancing stress assessment techniques to enhance tailored and immersive gaming experiences through Virtual Reality in horror games. We provide detailed insights into our collected data, which includes physiological measurements, motion behavioural data, and participants' self-reported stress levels. Additionally, we conduct an in-depth analysis on individual participants to delve deeper into the dynamics of stress experienced by each player. Results achieved give evidence that the measurement of motion behavioural data, exclusively collected from the headset, well compares to that based on electrodermal activity (EDA), more classically related to stress assessment. Data are made publicly available athttps://zenodo.org/records/15025199.

A critical challenge in the creation of Non-Playable Characters (NPCs) lies in the alignment between personality traits and emotions with the accurate portrayal of facial expressions. A mismatch between these two character’s aspects or the absence of effective synchronization between them could damage the believability of the game, with subsequent negative impacts on the player’s level of immersion and experience. This research introduces FACial EXpressions (FAC.EX), a software module crafted to enhance video game development by endowing NPCs with nuanced facial and internal responses during dialogues. Insights collected from feedback provided by 20 volunteers, including gamers and developers, affirm the perspective effectiveness of the module in simulating human-like facial expressions and emotions. The obtained positive results lay the foundation for potential future extensions aimed at meeting the dynamic requirements of the evolving game industry.

In this work, we explored the advantages of dynamic game balancing using players’ affective state introducing StrEx, a plugin designed to modulate the stress level induced by a video game in an unobtrusive way. The proposed plugin is also intended to validate results obtained by [1]. Our system collects motion behavioral data and updates a model of the player’s stress level to guide the transitions of a Finite State Machine which regulates the stress level induced by the game through the generation of game content. We designed and developed a virtual reality horror-survival game, with the aim of testing the system functioning. Our approach shows promising potential to create more immersive and engaging video games exploiting affective-based adaptation.

Abstract In this study we propose an approach to assess the fear of heights through a 3D virtual reality environment. We show that an immersive scenario provides a suitable infrastructure to such purpose, when supported by related behavioural and physiological measurements. Our approach is grounded in the principled framework of constructed emotions. This allows to shape fear detection as a case of categorical perception, which is amenable to be formalised as an unsupervised learning problem. Meanwhile, it paves the way for addressing meaningful physiological parameters for the assessment. Gauging fear of heights in individuals, beyond its theoretical relevance, is cogent for the early discernment of workers who are unsuited for operating at altitude and who may require to undergo specific training or, eventually, to be recruited for different positions.

In story-driven video games, such as Role-Playing Games (RPGs), a static and repetitive interaction with Non-Player Characters (NPCs) can negatively impact fun and immersion. On the contrary, an NPC able to show emotions and endowed with a personality that matches its behavior can keep the user engaged for a longer time. Unfortunately, this aspect has not yet been fully investigated. We propose Moody5, a preliminary solution designed to help game designers create “personality-biased” agents able to interact in sensible ways in the framework of interactive storytelling. In particular, it supports the creation of agents that exploit the Goal-Oriented Action Planning (GOAP) technique to reach their goals but whose chain of actions and quality of the interaction with the player are dynamically affected by personality and emotions. To obtain this result, we have borrowed ideas from the Big Five theory [1] and the Emotion Facial Action Coding System (EMFACS) by Ekman & Friesen [2]. We validated the proposed solution in a narrative test scenario inspired by the Harry Potter universe. Our preliminary survey demonstrated that Moody5 could improve the gameplay experience and replay value while providing a helpful Unity plugin for game developers.

Training agents to play in contemporary multiplayer actions game is a challenging task, especially when agents are expected to cooperate in a hostile environment while performing several different actions at the same time. Nonetheless, this topic is assuming a growing importance due to the rampaging diffusion of this game genre and its related e-sports. Agents playing in a multiplayer survival first person shooter game should mimic a human player, hence they should learn how to: survive in unexplored environment, improve their combat skills, deal with unexpected events, coordinate with allies and reach a good ranking among the players community. Our aim has been to design, develop and test a preliminary solution that exploits Proximal Policy Optimization algorithms to train agents without the need of a human expert, with the final goal of creating teams composed only by artificial players.

This short paper presents the second international workshop on Games-Human Interaction - GHItaly 2018. The goal of this series of workshops is to focus on advanced aspects of the design and development of game interfaces. The quality of the resulting interaction is a highly relevant issue for creating an engaging and satisfactory user experience, especially when deeply multidimensional artefacts such as video games are concerned.

In recent years we are witnessing an increasing interest of young players in Multiplayer Online Battle Arenas (MOBAs). In a MOBA, two or more teams compete for resources on a limited map with real-time interactions. In order to achieve the required level of coordination, network performances must offer to each player an adequate and uniform Round Trip Time (RTT) to the game server. Unfortunately, different ISPs will give different RTTs based on technical and commercial settings. In this paper, we define an overlay network to convey all the team traffic through the teammate with the lowest end-to-end delay to the game server. By doing so, we leverage on the peering between ISPs, usually offering better performances due to commercial agreements, to obtain an homogeneous and bounded delay for all team members. The proposed solution has been tested using the popular game League of Legends. In this paper preliminary, and promising, results are presented.

One of the most profitable and emerging high-tech markets is the one that involves games for PC and consoles; a market that is growing year by year and that is rapidly evolving. Several big game corporations are implementing now the remote video streaming through the domestic network between two devices; a feature that regards not only PCs but also consoles. This paper investigates one of the main services of this type, the Steam In-Home Streaming, to analyze the generated network traffic when considering different types of game. Gathered data can help to understand whether this type of service can actually be supported by today's regular Internet connections.

In these last few years we are witnessing a tremendous change in the way video games are developed. On the one hand, large development teams with a multi-layered organisation are employed. On the other hand, we see an increasing request for online services and functionalities. Combining these two trends together usually results in large projects involving parallel and distributed systems. Despite the adoption of team-oriented source code and asset repository managers, code testing and debugging is still left to human direct management. In particular, distributed debugging is a complex problem due to the synchronisation required between network nodes to correctly reconstruct the sequence of events leading to a malfunctioning feature. To solve the aforementioned problem, we designed and implemented DREAD: an architecture to support distributed debugging in real-time games. When adopting our architecture, developers will record events on edge systems, collect them on a centralised sync, and then consolidate everything in a synchronous way. Following this approach, it will be easily possible to detect unexpected software behaviours and trace back to their causes.

In the last few years we have witnessed a tremendous change in the way game developers are required to deal with software production.We moved from small groups building the application ground-up to large coordinated teams with hierarchical organisation.To support this transformation, game developers are now using integrated development and execution environments called game engines.Among all possible gaming platforms, mobile ones are proving to be a challenging ground due to their intrinsic requirement for game engines to deploy the final application on a distributed system.In this paper we discuss about requirements for next-generation game engines for mobile devices.In particular, we propose a variation of the standard approach for game engines architecture pushing from a monolithic architecture toward a distributed one.In our solution, the mobile game engine becomes modular and lower the distinction between client and server side.

Among the many uses of Artificial Intelligence techniques in video games, one particularly relevant from the perspective of the entertainment of the player is the ability to mimic believable behaviours in non-playing characters for first-person-shooter games. In our opinion, the solutions commonly adopted in the industry could be improved by simulating decision making under condition of incomplete information. To tackle this aspect, we propose a perspective approach that pairs behaviour trees to a simplified Publisher-Subscribers communication pattern.

In this paper, an approach and a rubric for measuring commitment to computer-supported collaboration in student teams is presented.

In these last few years we are witnessing a change in the way video games are implemented. Starting from an early age, where a single developer was sometimes in charge of the whole creative process, we have moved now toward extremely large groups with a multi-layered organisation. This increasing complexity of team organisation, together with a tremendous growth of projects size, calls for the adoptions of development approaches leveraging on scalability and distributed computing environments. Unfortunately, today's development and execution environments for games (usually called game engines) are suffering from a number of architectural constraints. As a result, we strongly believe current engines will not be able to provide the flexibility and scalability required by game developers of the next generation. To overcome the above limitations, in this paper we propose SMASH (Stackless Microkernel Architecture for SHared environments): an architecture where a game engine is decomposed in several dynamic and independent software modules interacting via a microkernel-like message bus. Game modules can just be inserted, debugged, and removed from a running engine once its internal messaging protocol is clearly defined. Moreover, following this approach, game modules can be dynamically dislocated on multiple machines to obtain a truly distributed, scalable, and fault-resilient system where adaptation can be achieved mostly without downtime.

The market penetration of in-home entertainment systems is playing a crucial role in the diffusion of interactive multimedia services. In this context, thin-client game systems have received a lot of attention, shifting the computational burden of the game play toward the server while the client renders a fat video stream. This paper proposes an analysis of the network characteristics of the Remote Play for PlayStation 4 and PlayStation Vita, providing some insights on the network dynamics of this system under different game types. The measurements involve video games of different genres, analyzing the bitrates, the packet size, capturing the dynamics of the whole streaming session. Results indicate that the service generates a large quantity of big packets downstream and smaller and lesser packets upstream. Gathered data can help to understand if this type of service could be offered through the today's normal Internet connections.

This paper investigates one of the main game streaming services, the Steam In-Home Streaming, to analyze the generated network traffic. Gathered data can be used to model this type of traffic in simulations and to determine whether it could be supported by Internet connections around the world.

In these last years, we have assisted to a skyrocketing diffusion of Massively Multi-player Online Role-Playing Games (MMORPGs) and Massively Multiplayer Online Games (MMOs or MMOGs). In these environments, which are complex socio-technical distributed systems, a huge amount of players interact to have fun and develop their characters. Looting Systems (LSs) help allocating valuable in- game objects, as fairly as possible, among the participating players. The medium/long term effects of the adoption of different Looting Systems on players have not yet been adequately investigated, in spite of the fact that they could impact heavily on players' satisfaction and hence on their "fidelity" to a specific game service. In the present work, we simulate the impact of several LSs on different players base, offering hints for reflection and further investigation to MMOs developers.

In these last years the growing availability of personal mobile devices has boosted the demand for mobile services offered based on location and context. Mobile gaming services are, of course, no exception. Unfortunately, the 3G networks infrastructure struggles to keep pace due to scalability limitations and a pull-based service model. One feasible solution, also for gaming, is to adopt an Opportunistic Network (ON) to exploit unplanned contact opportunities between players to perform data exchange and forwarding in ad hoc mode. When designing a game for an ON, the main issue is about forecasting the feasibility of a given gameplay when applied to a real - and complex - environment. In this paper we address this issue proposing an opportunistic game that is meaningful for the category of collaborative puzzle games. The game is evaluated by means of simulations on the topology of a real city in order to understand its scalability and setback on the gameplay.