Feature: 'Creating Credible Obstacles In Games'

'Why can't I jump over that wall?' In this intriguing design article, Sidhe's Gareth Griffiths (Gripshift) spans Halo to Half-Life to examine usability-related issues - and solutions - for frustratingly invisible and unbreakable barriers in games. As with real life, gaming worlds are filled with barriers and boundaries meant to block our path or force us to find another way around. While barriers are to be expected, problems arise when the barriers haven' been designed to be distinctive. In order to ensure that their barriers don't confuse players, designers need to keep in mind two key principles of Human Computer Interaction (HCI): visibility and affordance: "In HCI texts, visibility and affordance applies to the controls that users can see. Donald Norman defines visibility as 'Controls need to be visible which implies that there is good mapping between the controls and their affects. For example, the controls on a driver's dashboard have good visibility whilst video recorders have not.' Affordance is a technical term that refers to the properties of objects and how they can be used. A door "affords" opening. However, in HCI, what is more important is perceived affordance. This entails what the person thinks can be done with the object. Does the door suggest it should be pushed or pulled? So how does this translate into games and game design specifically? Well for our discussion, we are looking at the game-world itself - the actual environment - and therefore we need to ensure that the players are always able to see their path through the game. We should never have a situation whereby the player ends up at one point just sitting there, scratching their heads and unable to figure out where to go. This is not the same as a game which requires the player to figure out where to go." One example Griffiths cites as a disruptive barrier is the barrier that appears seemingly out of thin air to prevent players from escaping areas, forcing them to fight enemies before they can continue. Unfortunately, despite its age, this type of barrier is still commonly used in games today: "Kameo has a forest level where giant branches suddenly grow up from the ground and then go back in it when the bad guys are dead (good job the branches know all of this!) whilst Devil May Cry 4 has magically appearing red webs that halt progress. Again, this vanishes when everyone is killed. Do we really need these kinds of barriers? By now players tend to simply roll their eyes when these appear because it's such a cliché. From a usability perspective it is detrimental to the play for three reasons: 1. The player knows what is about to happen, there is no longer the element of surprise 2. The player is now constricted in an area which seconds before was not constricted. Why? 3. The flow of the game becomes very disjointed" You can now read the full Gamasutra feature on creating credible obstacles in games, which includes examples of barriers that often frustrate gamers and how to make your barriers more usable (no registration required, please feel free to link to this feature from other websites).