Before playing, gamers must wait for the game to load. While the effects of waiting on user quality of experience is well-studied for some domains, the effects of wait times on game players is not known, nor is the impact of computer system components, such as the processor or graphics card, on game loading times. We present results from a user study that evaluates the impact of game loading time on quality of experience using a custom tool that simulates game loading and collects player ratings. Analysis of the results shows game loading time has a pronounced effect on player quality of experience, but differs based on the individual game time and game load content. Results from our subsequent measurement experiment show the potential to reduce game load times through hardware upgrades – type of processor and graphics card have significant effects on game load times, but type of storage device less so.

For gamers, high frame rates are important for a smooth visual display and good quality of experience (QoE). However, high frame rates alone are not enough as variations in the frame display times can degrade QoE even as the average frame rate remains high. While the impact of steady frame rates on player QoE is fairly well-studied, the effects of frame rate variation is not. This paper presents a 33-person user study that evaluates the impact of frame rate variation on users playing three different computer games. Analysis of the results shows average frame rate alone is a poor predictor of QoE, and frame rate variation has a significant impact on player QoE. While the standard deviation of frame times is promising as a general predictor for QoE, frame time standard deviation may not be accurate for all individual games. However, 95% frame rate floor -– the bottom 5% of frame rates the player experiences –- appears to be an effective predictor of both QoE overall and for the individual games tested.

While target selection in a 2D space is fairly well-studied, target selection in a 3D space, such as shooting in first-person shooter (FPS) games, is not, nor are the benefits to players for many latency compensation techniques. This paper presents results from a user study that evaluates the impact of latency and latency compensation techniques on 3D target selection via a bespoke FPS shooter. Analysis of the results shows latency degrades player performance (time to select/shoot a target), with subjective opinions on Quality of Experience (QOE) following suit. Individual latency compensation techniques cannot fully overcome the effects of latency but combined techniques can, letting players perform and feel as if there is no network latency. We derive a basic analytic model for the distribution of the player selection times which can be part of a simulation of a full-range of FPS games.

Competitive first-person shooter games are played over a network, where latency can degrade player performance. To better understand latency’s impact, a promising approach is to study how latency affects individual game actions, such as moving and shooting. While target selection (aiming and shooting at an opponent) is fairly well studied, navigation (moving an avatar into position) is not. This paper presents results from a 30-person user study that evaluates the impact of latency on first-person navigation using a custom “hide and seek” game that isolates avatar movement in a manner intended to be similar to movement in a first-person shooter game. Analysis of the results shows latency has pronounced effects on player performance (score and seek positioning), with subjective opinions on Quality of Experience following suit.

Players of first-person shooter (FPS) games, such as Counter-strike: Global Offensive (CS: GO), seek low latencies in order to play well and have fun. Even network latencies as small as 10 milliseconds may decrease accuracy, score, and Quality of Experience (QoE), degredations that may be exacerbated for some weapons. This paper presents results from 40+ person user study that measures the impact of network latencies on players for the FPS game CS: GO. We setup a testbed where participants played 20+ rounds of CS: GO with controlled amounts of network latency with either a mid-range, rapid fire, high-precision weapon (an AK-47 assault rifle) or a close-range, slow fire, lower-precision weapon (a Nova shotgun). Analysis of the results shows even network latencies under 100 milliseconds degrade player performance (accuracy and score), avatar movements, and QoE, with the impact on player performance more pronounced for the assault rifle compared to the shotgun.

Video game play is among the most popular forms of entertainment in the world and eSports is a multi-billion dollar industry. Esports gamers, and competitive gamers more broadly, want fast game systems to maximize their chances of winning. In general, the faster the game system, the lower the latency between a player’s action and the intended outcome. But how much small reductions in local latencies benefit competitive players is not known. This paper presents results from a 43-person user study that evaluates the impact of system latencies for high-end gaming systems (below 125 ms) on experienced Counter-strike: Global Offensive (CS:GO) players. Analysis of the results show pronounced benefits to CS:GO player performance (accuracy and score) for even small reductions in latency, with subjective opinions on Quality of Experience following suit.

Understanding the effects of latency on interaction is important for building software, such as computer games, that perform well over a range of system configurations. Unfortunately, user studies evaluating latency must each write their own code to add latency to user input and, even worse, must limit themselves to open source applications. To address these shortcomings, this paper presents EvLag, a tool for adding latency to user input devices in Linux. EvLag provides a custom amount of latency for each device regardless of the application being run, enabling user studies for systems and software that cannot be modified (e.g., commercial games). Evaluation shows EvLag has low overhead and accurately adds the expected amount of latency to user input. In addition, EvLag can log user input events for post study analysis with several utilities provided to facilitate output event parsing.

When software and hardware processes cause delay between an input and an output, consequences can be both harmful and annoying. In games, this type of delay can cause actions to lag behind a player's inputs. Studies on delayed game actions show negative impact on both player performance and quality of experience. Further research could expand upon this knowledge with more robust data modeling and analysis, as well as a wider range of actions. This paper describes publicly available datasets from four user studies on the effects of delay on the fundamental game action of selecting a moving target with a pointing device. They include performance data, such as time to selection, and demographic data, such as age and gaming experience. Example analysis illustrating the use of the datasets is shown, including comparison of pointing devices, demographic analysis with performance, and analytic modeling.

Esports gamers, and competitive gamers more broadly, want low network latency to maximize their chances of winning - in general, the lower the network latency, the less time between a player's action and the intended outcome. But how much small reductions in network latency benefit competitive players is not known. This paper presents results from a 25person user study that evaluates the impact of network latency on experienced Counter-strike: Global Offensive players. Analysis of the results shows pronounced benefits to player performance (accuracy and score) for even small reductions in network latency, with subjective opinions on Quality of Experience (QoE) following suit. Latency compensation - a software technique to mitigate the effects of latency - significantly improves player performance and QoE.