Friday, November 23, 2012

Game Design: Static vs. Random Content

Looking through GameFAQS.com today got me thinking about static content and random content. In terms of game design, what are they?

Static content never changes in a game, no matter how many times it is played. It can be a level design, enemy placement, or a puzzle. Most games released in the past typically use static content. Static content still makes up a large majority of games released today.

Random content is procedurally generated based on some input seed. Computers cannot generate truly random numbers, but can come close enough by taking an input value that is hard to control, such as the time of day down to the second, and using it to generate a predictable value based on a random number generation algorithm. This means a game can change the content it presents based on any number of input values. Level designs can change, enemy placement can change, and even the starting state of a puzzle can change.

Both methodologies have advantages and disadvantages. Replay value of a game is one area that is affected by the choice of using static content or random content. For illustration purposes, let's take a look at Resident Evil, originally released on the PSX in 1997. The game state is the same each time it is played. Each item and enemy is in the same spot each time it is played. Each time the game is played, it becomes easier for the player to plan and map out his approach since he knows what to expect. When using randomized content, such as the case in Diablo, released for the PC in 1996, this is not the case. Diablo features randomized dungeon layout, randomized enemy locations, and randomized item placement and drops. Each time the player plays through this game, he is limited in planning his approach. He can set up his character for different possibilities, but does not know the absolute layout of the dungeon or the absolute enemy positioning. Even though games like Diablo feature randomized level layouts and enemy positioning, the game still gets easier each time it is played. The player does not know the absolute enemy positions, but he should get a general idea of the general enemies he will face in each area of the game. The Butcher, for example, is a boss character that is always found on the second level of the Cathedral. As we discussed earlier, randomized content is not truly randomized but rather procedurally generated by a computer in order to appear random.

Some games attempted to blur the line between static content and random content. Resident Evil 3 was the first Resident Evil game to feature variable enemy placement and item placement in a static world. Some puzzles could also have different starting states, requiring game guides to determine multiple solutions for the player seeking assistance. Unfortunately, Resident Evil 3 only included two or three states or locations for puzzles and items that featured random placement. After two or three plays, the player would likely see all configurations for each design.

Some independent games, such as Dwarf Fortress, like to be as random as possible. Upon setting up a game in Dwarf Fortress, the game prompts the player to generate a new world. Dwarf Fortress uses various algorithms to model terrain and then flesh out multiple generations of history for this world. Races rise and fall, erosion and weather changes the landscape, and characters end up migrating to end up in a different area of the world than when they started. Once this world generation is completed, it is open for the player to explore however he wishes. There is very little guidance and limitless options about where to travel, where to build, and who to talk to. The downside of this level of randomness is the lack of structure to the game. Many players are put off by the lack of guidance and abandon the game due to this. Imagine spending five hours building a character in Adventure Mode and then running across an enemy that is far too strong. The character is now dead, and in Dwarf Fortress, death is permanent. This level of freedom and unpredictability appeals to a niche genre of gamers, but is not for everybody.

When designing a game, you need to be aware of your audience. You also need to be aware of your game genre. Some genres do not require any sort of randomized content. Sports games should have schedules and rosters that mimic the real world. They should not be jumbled up as this can lead to clustering of star players on few teams, lending those teams an unfair advantage, and an unrealistic schedule. This may put off a large number of fans that would prefer to play a game this is closer to their actual sport. RPGs on the other hand lend themselves well to randomly generated content. Many RPG fans enjoy games that offer a high degree of replayability. This does not mean that RPGs should all be randomized, though. Replayability can still be offered through branching storylines that requires many playthroughs before the player is able to see all options.

The real challenge for determining whether to use static content or randomized content comes in determining what your target audience wants and striking a balance between fun and difficulty. Games that are randomized to a high degree are usually more difficult than games that feature static content. The player is not able to plan a specific approach since level design and enemy placement is not static. The player also has no ideas which item he will find or need for specific areas, or if his character is even strong enough to survive an area. Guides written for randomized content will be vague when compared to guides written for games with static content.


Static content versus random content is an important design decision. It affects many facets of game, from replayability to difficulty to target audience. The choice needs to be made at the design stage in order to get the team on the same page. Static content is easier to develop and implement, but may be harder to change. Once the static content is implemented into a game, changing it would mean a new design for the entire area. Randomized content is harder to develop, but once fully implemented can be easily changed by changing specific inputs. Games that use both need to be designed very carefully in order to prevent static events from being broken by randomized content.

In terms of game design, I believe a mix is best for most games that have the option to implement either. Good games feature guidance that is appropriate for the target audience. If the target audience is sandbox gamers, then very little guidance is needed. If the target audience is young children, then a high level of guidance needs to be implemented.

The only area of game design where I like to seen purely randomized content is concerning game puzzles. Most RPGs, shooters, and action and adventure titles feature them. Most of them are static, and are easily solved with the assistance of a game guide. I believe puzzles should be designed better than bring key A to lock B. A puzzle should be self-contained and started in a randomized initial state. Take the example of the "Lights-Out!" inspired door lock from Resident Evil. The puzzle has the player hit buttons on a 3 by 3 keypad. Each time a button is hit, its state is switched from lit to blacked out or vice versa. All surrounding buttons are also switched, similar to the children's puzzle game "Lights-Out!". The puzzle is solved the same way each time. If the player found a note earlier in the game, the key code to solve the puzzle is given. This puzzle can be initialized to a random starting state each time the game is played, and the note can be generated to give a solution to each generated puzzle. This would prevent players from being able to breeze through the puzzle without finding the note or at least taking time to think about their moves before touching the key pad. Guides would also be unable to assist the player by providing the definitive answer. Instead, guides would need to switch to teaching the players  how to think and solve the puzzle for themselves. If this turns off too many players, then the game designer may need to revisit including puzzles in the game in the first place.

No comments:

Post a Comment