As soon as a “stable” version of the whole (or just a discrete part of) game design is available, indicative electronic prototypes of the game can be developed showcasing the alternative interactive properties of its user interface for the different target user groups. The usability and accessibility of these prototypes should definitely be evaluated with representative end-users. In this respect, a quick, handy and very effective informal evaluation method is thinking aloud (Nielsen, 1993).
According to this method, an evaluator (or sometimes even more) observes a gamer interacting with the system, asking for vocalisation of thoughts, opinions and feelings, in order to understand the gamer’ s mental model, the way she thinks and performs tasks and find out any mismatches between the user’s mental model and the system model. Conversations are usually recorded so that they can be analysed later on. Furthermore, to support the evaluation process, a list of indicative tasks is used, that prompts participants to explore the full game functionality available.
After playing the game, a small debriefing session can be held, where participants are asked about their overall impression of their interaction with game and personal preferences, likes or dislikes, as well as for suggestions regarding potential improvement and modifications.
The outcomes of this step can considerably aid in validating, correcting and updating design decisions, as well as in developing new ideas for improving the accessibility and playability of the final game.
When the design specification is considered as “mature,” it can then be propagated for further development. Of course, as parts of the game and its functionality are being developed, it is highly desirable to regularly perform usability and accessibility testing.
A basic design differentiation between a turn-based board game, such as chess that was used as an example up to now, and action games is the “degrees of freedom” along which the game can be modified in order to become accessible (see Figure 7). More specifically, in the case of board games, only the user interface (i.e., the way the game is presented and controlled) can be adapted to better match a particular player’s characteristics.
The game’s rules (logic) and content are fixed and any deviations are not possible. Then again, action games are more flexible in this dimension, since they usually have a main goal, but they do not impose restrictions on how this can be achieved and do not have any globally established strict rules and specific content.