No one wants to play games that are either frustrating or difficult for the wrong reasons. The best way to make sure that unintended problems do not hinder enjoying the game is to take usability into account in game development. This article presents how this can be done and what kind of results to expect.

Usability is an integral part of software development and has been so for the past 20 years. For one reason or another, usability has not gained similar popularity in game development. This, however, is about to change. Ease of use and optimal user experience are already important in games and will become even more so in the future.

Usability is about maximizing effectiveness, efficiency and satisfaction. This definition originates from the traditional software industry, but it translates well to game development. In games, usability is about delivering a better and deeper experience with less unnecessary interruptions or challenges that have not been designed by the developers.

There are many reasons why usability is important in games. For one, playing games is voluntary. If the player has to struggle with problems that make playing less fun than doing something else, then there is nothing to stop the player from switching off the console. This is a serious risk as the user experience is very sensitive to usability problems. Even the smallest glitch or hiccup in the user interface may render an otherwise good game into a rather annoying experience. For example, if managing the inventory in a role playing game is not fluent enough or restarting a race in a driving game is tedious the player is not likely to enjoy playing the game.

Another reason why usability is important in games is the competition. Competition in the market is fierce. The gamers can choose which game to buy from a wide variety of titles; if the controls are not fluent in one soccer game, there are five more titles left from which to choose. Usability is one of the key factors that make the game stand out of the crowd.

The delicacy of the user experience and heavy competition actually make usability more important in games than it is in other software. There are not too many word processors to choose from, and having fun at work is not usually a top priority.

There are also other reasons why ease of use is important. One of them is that modern games are large and complex programs. In even the most focused games there are tons of menus and ways to interact within the game, not to mention games like the Grand Theft Auto series. Usability is important when making a game as easy and intuitive to play as possible. Good examples of complex games made easy are World of Warcraft and Xbox Live games. Both have succeeded in making traditionally difficult multiplayer gaming easy.

Usability is also important for the future of gaming. For gaming to continue to increase its popularity, the ease of setting up games and a fluent gaming experience are of the essence. This is because newcomers are not familiar with the conventions and common pitfalls of gaming. For them, learning the peculiarities that old gamers are already familiar with can be too much.

This Article

The focus of this article is not only to tell why usability is important in games, but also to introduce two usability methods and the kind of results they yield. The methods are expert evaluation and usability testing.

It will be presented how these were applied in the development of Frozenbyte's Shadowgrounds (www.shadowgroundsgame.com) game. Adage Corporation (www.adage-usability.com) was responsible for the usability related activities in the project. Before moving on to the methods, the game will be presented briefly.

Frozenbyte's Shadowgrounds Game

Frozenbyte Inc. is an independent games studio, based in Helsinki, Finland, founded in year 2001. Frozenbyte is currently working on a PC game called Shadowgrounds, which is to be released in the third quarter of 2005.

Shadowgrounds is an action game viewed from the top-down/3rd person perspective (see Figure 1). The main features of the game are adrenaline-pumping old-school action, realistic lighting, destructible environment and upgradeable weaponry.

	Figure 1. Intense battles, lightning effects and upgradeable weapons are key elements of Shadowgrounds.

Usability Expert Evaluation

In a usability expert evaluation, usability experts review the game and search for potential usability problems. Based on both their knowledge and experience they review the game systematically and report the findings.

In a typical expert evaluation three usability experts review the game. The experts first evaluate the game independently. After that the experts have an evaluation meeting together. In this meeting, the usability problems found are discussed and rated for severity. After that a report is written where the usability problems found are listed systematically. For each problem there is a title, severity rank, and a detailed description of the problem. A solution to each problem is also suggested.

This process takes approximately a week. Preliminary results, however, can be given in a few days. After handing in the final report, a meeting between the usability experts and the game developers is arranged. In this meeting, the findings are discussed in more detail, and the usability experts can answer questions that come about from the report.

Expert evaluation is a very flexible method, and it can be done at almost any point of game development. In the case of Shadowgrounds the expert evaluation was done approximately six months before the planned deadline of the game. In the version evaluated there was one playable level and the basic gameplay mechanics were implemented. Everything was, however, not ready. For example, the destructible environment was not fully implemented yet, voice acting was missing, and many smaller bugs were still present.

It is also possible to conduct an expert evaluation even in earlier stages of game development. For example, menus and displays can already be evaluated on the basis of paper prototypes, and potential usability problems affecting gameplay can be spotted from the design document. The earlier the expert evaluation is done, the easier and more cost efficient it is to make changes.

The depth and scope of an expert evaluation are also easy to change. For example, if there is a desire for constant input from the usability experts to the development process, then conducting several smaller usability evaluations with less experts and faster reporting may be a good idea.

In total 135 usability problems were found in the expert evaluation of Shadowgrounds. Out of these problems 2 were classified catastrophic, 30 severe and 60 intermediate. The remaining 43 problems were either minor or cosmetic. The distribution of the problems is illustrated in Figure 2.

	Figure 2. Classification of the usability problems found in the expert evaluation.

The number of usability problems found may seem high, but in reality it is not exceptional by any means. Expert evaluation gives feedback to almost every area of game development. In a typical evaluation, usability problems are found in menus, in-game displays, controls, gameplay and level design. Because of this, the total number of problems found can be quite high. Here are some examples of usability problems along with the game developers' view on the problem.

After the expert evaluation some of the most central usability problems were fixed to prepare the game for the usability testing that was scheduled to start two weeks later. For example, the map problem discussed earlier and minor usability problems related to the radar were fixed.