• Exploration — Most RPGs feature exploration as a significant part of the game play although it is more important in larger worlds like MineCraft and Elder Scrolls games. Skyrim is a great example of a modern game that shows how fun simple exploration can be. Walking from A to B in Skyrim is rarely as simple as going in a straight line for 10 minutes as it is hard not to explore and end up taking several real-time days to finally get where you were going (assuming you actually remember). It is still a minor part of a lot of other types of games including strategies and FPSs where a certain amount of it is required just to survive or gain an edge over the competition.
• Creation — Creating things in games can include simple things like character creation or skill trees all the way up to the complete LEGO-like construction possible in MineCraft. While some game types, like FPS and puzzles, don’t have much creation aspect the sky is actually the limit in others. For example, in MineCraft or Skyrim there are a very large amount of in-game creation possible in addition to out-of-game modding. Adding or modifying content for yourself and others to use is really the ultimate creation game and one that is overlooked for the most part, even in games that feature it strongly.
• Collecting — Another category that you don’t see too many games focusing on. The only examples I can think of are Pokeman and Diablo. Diablo may seem a strange choice as a “collecting” type game play but the random item generation and loot system makes it relatively addicting. The player is encouraged to keep playing in search of a better/rarer/special item drop which could at anytime, the good old “just one more level” syndrome which is a great thing for a game to have. In working with elementary school children over the years I’ve noticed that collection type games such as trading cards, scavenger hunts, and item collection are a very strong motivator across all age groups.
• Competition — Competing not only takes on the obvious form of multi-player, which is an important or critical aspect of many games, but also in the form of competition against the computer or even against the player themselves. Most FPS games are a typical example of multi-player competition as are MMOs although with an addition non-PVP aspect. Single-player games usually have competition in the form of just “not dying” or from character creation and story progression (to defeat the boss you need more levels, better weapons/armor). A game like MineCraft has a relatively weak competition component, especially on lower difficulty settings where the challenge is mostly in the collection and building of things.
• Collaboration — This is the direct opposite of competition but a game can use both at the same time. For example, Team Fortress has very strong competition and collaboration parts to it. Competition obviously with the opposing team but collaboration within your own team is also vital for a winning strategy. Sharing can also be used outside of a multi-player setting in the form of content sharing: make a mod and share it with 1000s of other people. As previously mentioned, the combination of sharing and creation can be a very large driving force for people from both the creation/sharing side as well as just using the shared content.

So where does all this get us? I don’t think it is wise to just take a game, divide the categories up evenly and try to just get a little of everything but at the same time thinking about how game play features work alone and together can result in a better design in the end. If your game doesn’t have any of a particular category it doesn’t make that wrong but it has to be a conscience decision along with its consequences.

As an example let’s consider a MineCraft-like block world. It has 1 meter sized blocks and 16x16x128 block chunks, like MineCraft, and the viewing distance is a 9×9 chunks, or 144×144 blocks, with the player at the center.  As the player walks in one direction and crosses a chunk boundary the game has to generate new chunks in the distance which, in this case is 9 chunks, or 32768 blocks. There are corner cases when the player is walking perfectly on the X-Y diagonal where we might need to create 17 chunks at a time but we’ll focus on the average case for now.

Assuming the player is running at full speed in one direction at 4 m/s the resulting chunk generation rate is 2.25 chunks/sec. This basically means that if we had the chunks being generated in the background thread and we could perfectly predict what chunks were needed next, then the minimum chunk creation rate would be 2.25 chunks/sec. Since we will never be able to perfectly predict where the player will go next in practice we will likely need a higher chunk creation rate.

In a world with a larger view distance, say 17×17 chunks, the minimum chunk creation rate is increased to 4.25 chunks/sec. With a very large view distance, 65×65, it increases to 16.25 chunks/sec.

Why does this matter? It matters because if we want a real-time world generation with no “pauses” as the player explores it we have to be careful about the complexity and time required for the world generation. Simple methods like plasma/mid-point displacement are relatively quick but adding more complex generation like ridged-multi noise can be orders of magnitude slower. For example, in some older tests a 256x256x256 block world was created in 2 sec with simple noise but adding caves via ridged-multi noise raised that up to 60 sec. In our prior chunk creation rate examples this corresponds to a rate of 256 chunks/sec and 8.5 chunks/sec respectively.

So ultimately, while more complex world generation may be interesting and desired it is ultimately linked to the size of world we’d like to display. A larger world display, even with some Level-Of-Detail system may require a more simplistic world generation.