21 April, 2009
I recently got back from IMGDC and had a great time. Since I was traveling, it was a good excuse to bring along my Nintendo DS and play Castlevania: Order of Ecclesia, a game I got for Christmas last year. One interesting thing is that the citizens in town give you “quests”, like in MMOs.
And that’s where it got frustrating. The drops you require are randomly dropped. Ick!
This made me want to post something about the nature of randomness in games.
I’ve talked about random numbers in games before. One design challenge dealt with making randoms more fair in paper RPGs. An earlier one dealt with when to use different types of randoms in games. I recommend reading these posts and the comments to get some background.
Why so random?
What is the purpose of random? Games have included randomness, but why?
Let’s start with the classic “a series of interesting decisions” definition for games. What makes the choices interesting? One option is to have a large number of possibilities. Chess or Go are examples of games which have a large number of possibilities. Because of this, it is unlikely that people will play the exact same game twice. Note that neither of these games have a random element as a core part of the game.
As we reduce the game’s possibility space, choices become limited and therefore more likely to be repeated. Consider movement in a game like Monopoly, which is along a linear path around a board; this path is a much smaller possibility space than Chess a 64 space board in addition to sixteen different pieces of six different varieties. Note that the linear movement in Monopoly doesn’t actually require the player to make any decisions, let alone interesting ones.
So, game designers add randomness to this situation to force people to react to the situation. In Monopoly the dice rolls and decks of cards make the situation less predictable. The interesting decisions don’t involve movement as in Chess, but rather the purchase and trading of properties.
So, randomness is a way to add more possibilities to a limited possibility space. Let’s consider a computer game now; in an ideal raid situation in WoW, for example, a balance Druid will cast only about 5 different spells in a spell rotation. This is a pretty limited situation, even if people used a larger number of abilities.
How do we increase the possibility space with randomness? The Druid from might get a critical hit randomly and do a surprising amount of damage and gain too much aggro. Or, a randomly fired enemy ability might have taken some of the character’s mana and it has less resources to use for casting.
Note that player choices still influence some of these decisions. For example, a player can chose to adjust some stats to alter the chance of landing a critical hit. Or, the if the monster’s ability to drain mana has a range limitation, the player makes a choice if moving (and not being able to cast while moving) is worth not being affected by this ability. I believe this is an important part of good randomness: it still allows for players to make interesting choices.
What happens when the randoms take away or have no way for players to make meaningful choices? This is where we get bad randomness in games.
The most notable example in MMOs is the random drop for quests. If a quest requires you to get drops from an enemy, it can be frustrating if it seems to take a rather long time to get the item(s) you require. In a typical “random with replacement” system where an enemy has a less than 100% chance to drop the required item, it’s possible (even if not probable) that you may never see the drop. In this case, you have no way to increase the chance of a drop, the player’s only choice is to either cointinue killing the enemies or not, which means either trying to complete the quest or not. Not much of a choice.
This is the same situation I ran into with the Castlevania game for the DS I’ve been playing. The items I need to complete the quests (and open up more healing items and equipment) are randomly generated. Although the player can affect the drop rates somewhat by increasing the “Luck” stat, the same principle applies: it’s possible (even if not probable) that the item may never drop. On top of that, the monsters that drop the item are not specified, so without outside information you may not kill the right monsters.
Design motivations for bad randoms
So, why are bad randoms used? In the case of quest drops, it’s to make the content seem longer than it is. If the quester only had to find a kill one common enemy, the quest would seem short. Even killing a small number of enemies with a 100% quest item drop rate is likely shorter than a lesser drop rate. At 50%, the player has to, on average, kill twice as many enemies to get the same number of items. With randomness, the number killed will vary, making the quest seem less rote. Of course, we can reduce the frustration in this type of random by using a “random without replacement” system to put a cap on the number of enemies you must kill.
The other problem is that designers, like most people, don’t always understand how randoms work. It’s very simplistic to look at “gather 10 items with a 50% drop rate” and mentally average it out to 20 kills even though that’s not what it really means. In a simple “random with replacement” system it means that the player will have to kill between 10 and an infinite number of enemies to get the items required. Of course, this same lack of understanding of probability is the same thing that allows gambling, like the lottery, to get people to play.
Ultimately, the important thing to do is make sure that the player has meaningful input. Any situation where player input is meaningless, whether it involves random or not, can lead to frustration. Adding randomness to a lack of meaningful control is the shortest road to frustration in a game.
What do you think? What is the proper amount of randomness to an MMO game?