Randomness in Games

Chances Are 50/50 That It's Good Or Bad...

Randomness is often at the forefront of discussion on why a game feels fair or not. Obviously there are successful games that depend very heavily on randomization as a major mechanic like Yahtzee, Poker, or Carcassonne. 

In my experience, a player's feelings toward randomization comes primarily from how long they have time to react to it.  It also changes drastically when you consider whether it is applied as a boon or a punishment. If randomization seems to occur at the same point a punishment is determined, it seems much more suspect than if it occurs long beforehand. However, if a boon is randomized, one is rarely put off as long as it is clear what happened and why.

The degree to which something is considered random could also be in dispute:

• Tetris blocks are never completely random, although they are shuffled several turns in advance.
• Diablo's loot tables are somewhat random but have a pretty strict filtering system in place.
• Attacks in Risk use randomization, but the size of forces is still usually the determining factor.

Randomness Is Bad.

Random numbers should not be generated with a method chosen at random. - Donald Knuth

In games with random level generators like Settlers of Catan, Spelunky, or Minecraft, an unfavorable randomization is mitigated by the fact that you can prepare and plan to accommodate it.  When the level is seemingly generated "on the fly" like in Asteroids, Helicopter, or Tetris, you always have a situation which you can "blame" the computer for making you lose, regardless of the number of times the randomization occurred in your favor beforehand.

In many RPGs, the attack damage is often calculated at the time of the attack.  This is a means of keeping battle after battle from being rote but if the range of damage is too large, each encounter can feel like a simple roll of the dice.  Have you ever "whiffed" away in frustration at a boss who "crits" every time?  This is especially apparent when checking for traps in most RPGs.  You spot check, wait to see if you took damage, and if so, reload to roll the dice again.

So if you're using randomization to provide a challenge or to punish a player in some way, make sure:

• The player has time to react to the new information generated by random chance.
• The chance decision provides new gameplay, rather than simply providing an outcome. For example, spawn some monster instead of simply damaging a player if they fail a spot check on a trap.
• That you are providing some means of letting the player improve their chances of favorable outcomes.

Randomness Is Good.

Chaos in the midst of chaos isn't funny, but chaos in the midst of order is. - Steve Martin 

In games, the suspense of having a chance of getting something randomly from a chest, loot drop, or other action is huge fun.  In fact one could argue that it's largely the reason such repetitive play is tolerable in games like WoW, FrontierVille, or your favorite table in Vegas. Much discussion can be made about the subtleties of random reward schedules.  Suffice it to say that within each game, there exists a ratio of risk vs reward which should be applied to each boon.

Obviously repetitiveness can kill an experience and make it feel like work.  "Randomizing" helps extend the life of the game by providing variety in challenges and obfuscating the occurrence of rare opportunities. However, true randomness can often have the effect of being "too random."  In true randomness, there is a chance you could get the same Tetris piece 20 times in a row.

Games must usually have a hierarchy of events and scenarios, ranging from common to rare.  Within a game, a player may experience a range of random common experiences, to then get a chance at experiencing a random rarer one.  This nested hierarchy of sets of random events has the effect of making players play more of the game, but if used too much, it can make every encounter feel random.

If you're using randomization to provide a boon or variety to a player, make sure:

• The range of rewards are of similar value, interesting variety, and match the risk of the action taken.
• Players have the information to discern the rarity of loot or experiences.
• Players can improve their chances of encountering rarer or more favorable outcomes.

Well That Was Random...

We must believe in free will, we have no choice. - Isaac B. Singer 
 
Randomness is an absolutely essential tool in creating a game.  But (and I'll avoid a discussion on religion here) none of us want to feel as though our efforts are completely determined by chance.  We need to ultimately complete the feedback loop in which our preparation is in some small way validated, our plan for attack seems reasonable to us, and that we feel we will obtain new information and resources with which to formulate a better plan next time.  We need to feel progress.