Deeply Random Thoughts

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The really big VW problems

19 September 2004

I have read many a discussion on various newsgroups about issues in virtual worlds, such as class-based systems vs. skill-based systems, the best combat system, and what to do about spawning problems.

For whatever reason, most of the discussed problems don't impress me. From my POV, virtual worlds have a handful of large problems that dwarf the classed vs. classless (and ilk) discussions. These large problems are so huge that they may be unsolvable, or only solvable to the exclusion of other solutions.

Following are the major problems with virtual worlds, as I see them (in no particular order):

Sensory realism - Of course, looking at a 15" computer monitor with a pair of speakers is significantly inferior to real-life's sensory realism. True sensory realism requires many technologies to come together: At a minimum, a future VW experience should include much better 3D modelling, rendering, and animation that can currently be achieved, along with better sound. Add to this haptics, motion, smell, taste, etc.; humans have quite a few senses that need fooling.
User input - Player characters are controlled using a combination of mice, joysticks, and keyboards. Ultimately, user input needs to include speech recognition, face recognition (for emotions), gesture recognition, data gloves/suits, stress measurement, and maybe even mind reading.
Players - A world filled with other players has many advantages, which I won't bother to list. There are disadvantages though, the worst of which are cheaters and griefers. Further down the list are players getting in each others way as they play in the world, and players ruining each others immersion. Unfortunately, the solution to the problems produced by multiplayer environments is not to make a single player game, since that throws out the advantages of having multiple players.
NPC AI - Current NPCs are plain stupid. Those that fight are programmed with inferior combat tactics (probably so they're not too challenging), and as for their conversation skills, don't even try to start a conversation with a NPC. Most contemporary MMORPGs don't view NPCs as important, since they have so many players running around. I feel differently, that NPCs are necessary because their motivations can be controlled by the author; players can be coerced, but never controlled. Plus, as a player, I don't mind doing something nasty to a NPC because I know there isn't a real person on the other side.
Plot maintenance - Stories have a neat property called a "plot", wherein just about every element in a story "advances" the plot and leads towards the final conclusion. If part of the narrative fails to advance the plot, the author usually removes it. For some reason, people find plots satisfying, which is why stories use plots. Current virtual worlds do not bother with plots, however, because any plot the author designs will be instantly derailed by introducing a few (let alone several thousand) players into the world, even if they don't intend to derail the plot. The ultimate solution, I suspect, is to have AI (or real people) maintaining a semblance of plot in the background.
Personalization of content - The virtual world should know what the player likes and customise itself to the player's likes. This doesn't mean guaranteeing that the player will win, even if the player thinks they would like such a guarantee, because such certainty produces a world that the player won't like. Contemporary virtual worlds have limited content personalization, allowing player characters to wander to parts of the world that the player wishes. Furthermore, authors spend lots of thought and data collection figuring out what players (as a group) like to do. They do not, however, try to learn what activities an individual likes.
The static nature of the world - Contemporary virtual worlds are largely static. Some authors try to solve this (such as Asheron's Call) but haven't really succeeded.
Perplexity (physics) - In traditional VW lingo, the "physics" of the world controls what kind of actions a player character can take, and ultimately controls how complex this action can be. Speech recognition researchers used a term that worked better than "physics": "Perplexity" (in speech recognition terms) is a numerical representation of the amount of branching in the context-free grammar used for recognition. In plain English, if a speech recogniser knows that after hearing word X it will only hear words Y or Z, then the system has low perplexity. However, if after hearing word X the speech recogniser needs to listen for 5000 different words, the perplexity is high.

Virtual worlds do not allow for enough "perplexity"; they don't provide players with enough choices. In most MMORPGs a player can only talk to an NPC or attack it. What if the player wishes to wave at the NPC? Examine it? Spit at it? Give it a present? Play chess with it? Etc. They can't. Ultimately, perplexity is limited by the user input modalities.
Cost of content generation - Virtual worlds cost too much money to create. Costs will only climb higher as money is invested to solve some of the other problems listed here.
A virtual world must be similar to reality - Most television shows (sitcoms, cops, dramas, hospital shows) and movies are based on near-reality; they take place in the real world, but with a few modifications. A few more occur in the near past or future (historical dramas). Even fewer take place in a fantasy setting. None occur in 4.52 dimensional space. Virtual worlds have the same problems... most people's imaginations are limited to the reality we know.
The network - The Internet is slow, expensive, unreliable, and has a high latency. These problems will only become more pronounced as sensoral reality and user input are improved.

Are there solutions to these problems? Maybe. Below are listed some existing solutions.

How MMORPGs try to solve these problems

Here are some of the techniques that MMORPGs use to solve these problems.

Sensory realism	Up to half the MMORPG team is tasked with producing 3D models, textures, animations, sound recordings, and music.
User input	Rely on the mouse or joystick with occasional keyboard use (mostly as discrete buttons like AWSD).
Players	Expel cheaters and griefers. Make some activities, like player killing, impossible.
NPC AI	Generally ignored.
Plot maintenance	Generally ignored, although a few MMORPGs try to maintain a world plot.
Personalization of content	Generally ignored.
The static nature of the world	Generally ignored.
Perplexity	Keep the perplexity as low as possible since the user input and mass-market focus cannot handle anything more complex.
Cost of content generation	Expensive content is actually good for the large MMORPGs since it prevents competition.
Similar to reality	Mass market means that reality is king. Most contemporary MMORPGs occur in a fantasy or science fiction setting; this is in part because MMORPGs are not mass market yet, and even the fantasy/sci-fi settings are based on the real world with a genre veneer. (Example: Why do laser guns always look like pistols or machine guns? Why do aliens look like humans?)
The network	Some motion prediction algorithms.

How text MUDs try to solve these problems

Sensory realism	Generally ignored. To a text MUD player and author, text is superior to everything.
User input	Keyboard used to enter English sentences.
Players	Like MMORPGs, except that many MUDs encourage role playing.
NPC AI	Generally ignored.
Plot maintenance	Generally ignored, although a few MUDs maintain a world plot.
Personalization of content	Generally ignored.
The static nature of the world	Generally ignored.
Perplexity	English sentences allow for a much higher perplexity than MMORPGs, although perplexity could still be improved.
Cost of content generation	MUD content is very cheap to produce.
Similar to reality	MUDs are more likely to veer away from commonly accepted genres.
The network	Generally ignored since it's not really an issue, the network being fast and reliable enough for text.

How CRPGs and Adventure games try to solve these problems

And you thought I was only discussing about virtual worlds... Single-player CRPGs and adventure games have many of the same issues.

Sensory realism	Just like MMORPGs.
User input	Just like MMORPGs.
Players	Not an issue.
NPC AI	Because there aren't any other players, NPC AI is more important. NPC combatants are often more intelligent than their MMORPG equivalents. NPC conversations are often better too.
Plot maintenance	The plot is handled as a "string of pearls" where the user can wander around freely in the current "pearl" until they advance the plot and are moved to a new "pearl". Some plots include branches.
Personalization of content	Generally ignored.
The static nature of the world	As the plot advances, the world changes along with it.
Perplexity	Just like MMORPGs.
Cost of content generation	Just like MMORPGs.
Similar to reality	Just like MMORPGs.
The network	Not an issue.

How face-to-face RPGs try to solve these problems

And you thought I was only talking about computer games? Traditional face-to-face RPGs (like Dungeons & Dragons) encounter these same problems.

Sensory realism	Mostly imagination derived from speech. Maps, miniatures, and occasional sketches are also used.
User input	Players communicate their actions verbally to the GM, occasionally using hand gestures.
Players	Because only a small group of players are in a session, and they all know one another, cheating and griefing are fairly rare. The players (as a group) control the amount of role playing expected.
NPC AI	The GM supplies the AI.
Plot maintenance	The GM and players work together to produce a plot.
Personalization of content	The GM personalises the content for the players.
The static nature of the world	The GM changes the world based upon the players actions and the needs of the plot.
Perplexity	The GM handles the world simulation.
Cost of content generation	The GM produces the content, often on the fly, making it very cheap.
Similar to reality	This varies with the group, with some groups veering further away from reality than others.
The network	Not an issue.

How stories (TV, movies, and books) try to solve these problems

And you thought I was only talking about games? TV shows, movies, and books have many of the same issues.

Sensory realism	Books rely on the imagination for sensory realism. TV shows and movies have huge budgets devoted to sensory realism.
User input	Not an issue.
Players	Not an issue.
NPC AI	NPC AI is "baked" into linear narrative.
Plot maintenance	Plot is "baked" into the linear narrative.
Personalization of content	Since there are so many stories available, if one doesn't suit a viewer can always find another.
The static nature of the world	World changes are "baked" into the linear narrative.
Perplexity	Not an issue.
Cost of content generation	Books are cheap to produce. Movies are very expensive to produce, although their costs are dropping with technology.
Similar to reality	Mass-market TV and books are based on reality. Books, which are less mass-market, can escape some of the usual chains.
The network	TV has a network specially designed for it.

How the Holodeck tries to solve these problems

You thought I'd stick to reality?

Sensory realism	Artificial matter.
User input	Players exist within artificial matter, so there is no extra user input. (Although this limits their input.)
Players	Only guests and parasitic aliens are allowed in.
NPC AI	Great AI.
Plot maintenance	Not really specified, but I assume the great AI has something to do with it.
Personalization of content	Not really specified, but I assume the great AI has something to do with it.
The static nature of the world	Not really specified, but I assume the great AI has something to do with it.
Perplexity	Not really specified, but I assume the great AI has something to do with it.
Cost of content generation	Not really specified, but I assume the great AI has something to do with it.
Similar to reality	Players in the holodeck can't even take on a different appearance.
The network	Holodecks don't seem to be tied to a network.

Interrelated problems

The act of solving one of the major problems often causes the other problems to become more difficult... for example: Increasing sensory realism makes network speed and reliability that much more important, since players are likely to notice lag and dropouts.

Below is a list describing how solving one problem makes some of the others more difficult to solve:

Sensory realism	Increased sensory realism makes... User input becomes more important, so, for example, players have better control of the emotions that their players display. NPC AI more difficult because the animations/sounds will be good enough to convey emotions and subtle movements. Cost of content generation increases. Shows off problems in the network delay, throughput, and reliability.
User input	Increased user input makes... Network bandwidth higher.
Players	Solving player undesirable conflicts makes... NPC AI more important because the players spend less time fighting amongst themselves.
NPC AI	Increased NPC AI makes... Plot maintenance more difficult because NPCs want to choose their own directions. Does a NPC move the plot forward or act like it's personality dictates? Personalization of content is harder because NPCs won't necessarily want to do what the player wants them to do. Cost of content generation increases.
Plot maintenance	Improving plot maintenance makes... Perplexity is more difficult to achieve because a good plot often requires a low perplexity.
Personalization of content	Improving content personalization makes... Conflicts between players more difficult to solve, because even if the players aren't trying to conflict with one another, their personalization-goals might.
The static nature of the world	Making the world more dynamic causes... NPC AI is more difficult since NPCs must cope with the changing world. The cost of content generation increases.
Perplexity	A higher perplexity makes... Sensory realism more difficult to achieve. (TV/movies, with no perplexity, have might higher sensory realism). User input more difficult since the player has more options. NPC AI more difficult since it must respond to more conditions. Maintaining a plot is trickier since players have more ways to derail it. The cost of content generation rises. The world must resemble reality more. (Early video-games like Pac-Man were further from reality than today's games.)
Cost of content generation	Decreasing the cost of content makes... Since the solution to every problem almost always leads to an increase in costs, reducing content generation costs negatively affects the solutions to the other problems.
Similar to reality	Diverging reality causes... Sensory realism is more difficult... if your PC has a tail, how do you feel it? User input is more difficult... if your PC has a tail, how do you move it? Effectively increases the cost of content generation because the market is smaller.
The network	Improving the network causes... No problems that I can see.

Conclusion

A VW can't solve all the major problems since the act of solving some problems causes others to get worse. Most MMORPGs have decided that sensory realism is the most important problem, so they tackle that to the detriment of the other problems.