Last week we looked at how prop theory can clarify game design by identifying components of a toy chest containing the principal and central props used for the play of digital games. This week we continue to consider the first and third person fully-rendered fictional world but look at another aspect of the toy chest paradigm – the play sets within which the individual toys are used.

The Play Set

Beyond the dolls and models (and their various trimmings) lie the toys which make up the wider substance of the fictional world itself. These are like the child’s play set, within which individual toys are placed for specific games of make-believe. When a plastic Godzilla appears in the parking garage, we are playing monster attack. Similarly, the contents of the toy chest combine with the following props to dictate specific opportunities for play. In these cases, the toy metaphor often gives way to the paradigm of the film set, which in many respects is analagous to the child's play set.

• Sets and Locations: like a movie set, the environments that the avatar can explore can be thought of as sets, within which play can be staged. And similarly to a movie, it is also possible to make sets of such complexity that they constitute locations. What’s the difference? Principally just scale, but there is also the question of connectivity. If the game consists of a sequence of enclosed locations (as most FPS games do) or as a map which collects multiple enclosed locations (as many RPGs do) then set is the most appropriate term. But if the game is closer to an open or playground world then location is a more appropriate term. Either way, we’re referring to the environment of play purely as a spatial entity. Anything that can be interacted with within the set or location can be thought of as a different kind of prop.
• Scenery: anything in a set or location that doesn’t interact with dolls or models in any way beyond being physically present is simply considered scenery.
• Doors, Keys and Switches: connecting sets together (or embedding sets in locations or connecting locations together)  are doors, and these may require another toy – a key or a switch – that opens the door. The key prop has the characteristic of granting an additional ability to the avatar (it can open certain doors), while the switch prop simply changes the states of other props. The latter always risks creating puzzle-solving play, and restricting the appeal of the play to a smaller audience, since challenging puzzles always have a dominating effect on play.
• Climbing Frame, Slides and Trampolines: this first term refers to a toy that allows dolls to ascend or descend (including ladders, ropes, vines and anything else), the second a toy that allows dolls solely to descend on a specific path (including rope slides, chutes etc.), and the last a toy that allows dolls to ascend but not descend. These may influence play in certain ways, but rarely if ever dominate it.
• Obstacles: a specific kind of toy within a set or location that is overcome in a particular fashion, such as a gap separating a part of the set, a hole in a wall that must be crouched through, can be considered an obstacle. In many cases, the player’s doll may have the ability to bypass the obstacle using its basic abilities (in which case the obstacle is primarily a control challenge for the player), in others a specific tool may be required (in which case the obstacle may have a structural role in arranging the shape of the world). Doors and keys might also be thought of as a kind of obstacle, albeit one with a distinctive character of their own. The presence of obstacles has an influencing effect on play, but it does not dominate play in the way that weapons will.
• Map and Compass: the map is a prop which depicts the whole of a set or location, while a compass is anything (including a radar or GPS) that guides the player within the world. These two props are of vital importance! Games that use locations must have maps (and probably should have compasses) unless there is a good reason for omiting them, while games that have sets may benefit from maps but are more likely to be able to survive without them. The key issue in respect of these props is the complexity of navigation - and while more complex geography probably requires a map, the map will heavily influence the resulting play. It is worth remembering that just as not everyone can remote control a toy airplane, not everyone can read a map, and the presence of a map is a sign of a game unlikely to reach a true mass market audience. However, the gamer hobbyists who buy and play many different games are almost all map-literate, and thus most digital games will require decent map and compass props.

Other Props

There are other props which have radical effects on the play of games but do not fit into the toy chest or play set metaphor in quite the same way as those discussed in the previous two sections.

• Shops and Money: the two kinds of prop go together. If you have shops, you have money to spend in them. (You may also have a shopkeeper – a simple robot doll who mans the shop). The presence of money is a heavy influence on play, and is likely to encourage collecting and stockpiling. 
• Experience and Skills: Experience and character screens in RPGs can similar be understood as shops and money, albeit a different kind of money that represents acquired skill. Experience dominates play in almost every context – and modern console games are including these props in everything from FPS games to sims these days. 
• Tasks, Puzzles and Stamp Collections: typically consisting of a verbal objective (a narration prop) and an optional prize (a toy paid out for completing that objective), the task is a basic structural element of any game, usually presented to the player within the narrative as a mission or quest. Tasks may not seem like a toy, but we can easily find examples of toys with intrinsic tasks and puzzles. Consider the ball maze and its implicit task of guiding the ball to a target spot, or the Rubik's cube with its intrinsic ‘mission’ to solve the puzzle, or an I Spy book with its “stamp collection” to be completed. When the task is more like a Rubik’s cube, the play will be dominated by puzzles and the potential audience narrowed, while the “stamp collection” style has wider appeal (provided each “stamp” is comparatively straightforward to acquire) but can still heavily influence play. Indeed, in modern games Achievements or Trophies attach a stamp collection of tasks and puzzles to every hobbyist console game, which carries a severe risk of dominating the play of these games.

Embracing or Avoiding Domination

The props identified last week and this week are in no way an exhaustive list of the toys to be found in digital games, but collectively they demonstrate the general framework being proposed – one which draws parallels with children’s toys on the one hand and movie productions on the other to encourage thinking about the elements of games from an explicit viewpoint of play rather than of game.

Furthermore, the perspective brings to the fore the way in which various props can dominate or heavily influence the play of digital games. Weapons and toy soldiers dominate the play in any fictional world whenever they are a part of the toy chest, and models and obstacles carry similar (although less pronounced) risks. Money props – especially in the form of experience points – have a severe dominating effect. Another significant risk for domination of play occurs with tasks and collections, and particularly puzzles, each of which makes the play more rewarding for players willing and able to co-operate, but at the cost of closing down accessibility from anyone not open to that kind of play. (My comments on the way in which enduring hardship ultimately enhances enjoyment is relevant here).

It may be illuminating to pursue the reasons that certain props dominate play, and the way in which this domination necessarily creates a barrier for anyone uninterested in playing this way, since somewhere in this perspective lies valuable lessons for commercial game development – and invaluable opportunities for art games seeking to carve out new play experiences beyond the obvious tropes. By using prop theory as a lens, game design may be able to tease out more playful combinations of toys, or at least better understand how it is that the kinds of play we are presented so often end up in surprisingly narrow forms.