posted: July 19th, 2006
Raph Koster wrote an article talking about use-based skill systems in MMO’s and about how they worked out in Ultima Online and StarWars Galaxies. Just another example of synchronicity since I planned on following up A Distinct Lack of Class with a post about skill systems.
As I stated in my earlier post I’m really not a fan of class based systems. I find them artificial and I feel that too often they lead to odd methods of skill progression (beating up orcs to increase your ability to pick locks, as an example). There are some good points to class based systems, as I stated earlier, but I would rather try to find some way to bring as many of those advantages over to a skill based system than remain in a class based system solely for those advantages.
As I see it there are three main ways of handling advancement in a skill based system. The first is to have players earn experience that they spend as they see fit to advance their skills. A fair amount of tabletop RPG’s use this method since it is simple and easy to keep a track of. The biggest problem I have with this method is that it still leads to odd methods of skill progression (beat up orcs to earn the experience points you use to increase your lock-picking skills). This can be avoided somewhat by breaking experience into categories instead of a general pool, so the experience you gain from beating up an orc can be used to increase combat skills but not crafting skills. With a large number of pools this can quickly become too cumbersome for a tabletop game but with servers keeping track of a character’s stats it isn’t as much of an issue.
The second method I can see, and one I wouldn’t have even thought of until I tried Eve Online, is time based. You select a skill to ‘practice’ and after a fixed amount of time it improves. There’s no XP to earn, just time to spend. It’s an interesting approach, but I’m not 100% sold on it since a player who is highly active progresses at the same rate as someone who only logs in when they need to choose the next skill to train (an oversimplification, but you get the idea). Still, since the skill gain occurs in real time whether you are online or not it definitely reduces any feeling that you are obligated to grind in order to increase skills.
The last method I can see is, of course, the use-based method. Skills are increased as you use them. This, unfortunately, tends to lead to grinding, grinding leads to macroing, and macroing leads to the dark side.
Enter the law of diminishing returns. This isn’t something I’ve talked about yet but it’s something that I’ve started to consider as possibly being a very important item in design of an MMO. Yeah, ‘started to consider as possibly being’ is a pretty weak statement, but I’m certain of the idea yet, so I’m not about to trumpet it as a golden rule. Given that it has the ability to prolong enjoyment of a game by removing the importance of grinding, as well as levelling the field a bit between casual and hardcore gamers I can see a lot of potential in it, but I still need some time before I convince myself.
The law of diminishing returns is something that occurs in real life all the time and what it basically means is that as more energy is put into something the lower the return on investment is. This doesn’t mean that the return is less than it was before, simply that the return doesn’t scale linearly with the energy expended.
This is pretty much a universal constant, at least once certain minimums of expenditure are met, and the clearest example I can think of is a car. In order for a car to travel twice as fast it has to spend more than twice as much energy. This is because as speed doubles wind resistance squares. This is just one example of course. The world is full of others.
Learning, likewise, suffers from the law of diminishing returns. The longer a person spends trying to learn something without a break the more fatigued they become and the slower they will learn. A person who spends fourteen hours in a single day trying to perfect a skill will learn less than a person who spends two hours a day for a week trying to learn the same skill.
How do we translate that into a game system? Well, for starters I would consider breaking skill levels into ‘long term’ and ‘short term’ levels, much as human being have long term and short term memory. As a skill is used any gains from it go immediately into the ‘short term’ pool. Points drain out from this short term pool and into the long term pool at a rate based on how high the short term pool is. A short term pool that is higher will transfer faster than a short term pool that is lower
The catch is that the transfer rate isn’t linear but is an inverse geometric function. A pool that is holding a hundred points might transfer points twice as fast as one holding twenty five points, three times faster than a pool holding eleven points, etc. In the mean time the short term pool will additionally ‘bleed’ points faster depending upon how large it is. The points are simply lost and not converted to the long term pool. This rate however is linear, so a pool with a hundred points would drain away at a rate four times faster than a pool with twenty five points and nine times faster than a pool with eleven points. Thus, to continue progressing twice as fast as another player a person would have to spend four times as much energy.
Most of this would be kept hidden from the players for the sake of simplicity, but of course as Raph Koster points out, any system you create will eventually be analyzed and decoded by the player base. To help prevent or at least mitigate ‘min-maxing’ on the part of players all individual pools could be combined together for the purposes of transference and loss. A character with two pools at twenty five and one pool at fifty would transfer just as many points as a character with a single pool at one hundred, though the points would be split with a quarter of them going to one skill, a quarter to another, and the remaining half going to the third. Likewise the character would ‘bleed’ points at the same rate, again with the loss being divided between the three pools.
Obviously such a system would take some balancing to get the math right. Four times the work for twice the gain might be too much work or too little work, but the concept remains the same. As more energy is spent the character progresses faster, but the rate of increase is slowed so that the law of diminishing returns applies.