RNG
RNG stands for Random Number Generator. It is the device that allows Kevan to institute 'random chance' actions and determines success or failure for all actions.
It is sometimes called the Random Number God, As the RNG often seems to be a living being intent on screwing people over.
It is sometimes believed that the RNG will provide a linear success rate, 10 successes in 100 for a 10% skill/effect, 35 out of 100 for a 35% skill/effect, etc. This is untrue. RNG processes things in a sucess rate in accordance to Murphy's Law, divided by Moore's Law, multiplied by the Square Root of a Piece of Cake. Moore`s law states that CPU processing speed will double every 18 Months, and Murphy's law states that what ever the worst thing is, it'll happen. This means that every year-and-a-half computational beasts like the RNG will screw you over twice as much as they did before. This is because the RNG is a cold-hearted bitch that will take your heart out as quick as look at you. RNG will shaft you in ways that you didn't even know existed; we're talking Old Gods, The King in Yellow style abuse here.
You may choose to believe the damn RNG. This means you are a fool. RNG doesn't let you invest 5 searches into a hospital and give you an FAK. Lady Un-Luck is a chancy broad, and a chance is only a definite maybe, a possibility at best. Its a CHANCE, boys. 33% does not mean every third time a success, but it does mean for INFINITE counts of tries 1/3 will be successes.
Unfortunately, the RNG used by Urban Dead is not perfect. It isn't even close to perfect. The number for a 33% chance should approach 1/3 the more you perform the action, but in fact, does not. This is because the RNG is actually a pRNG. A Psuedo Random Number Generator. And the pRNG used by Urban Dead is liable to give you strings of "bad luck" so horrible that were it a fair RNG, you might want to start thinking about dodging lightning.
You ever search for a syringe 50 times and get 2? Blame RNG. You get killed by three flareguns to the face one-after-the-other? Blame RNG.
As Petrosjko once said: "There are good days, there are bad days, and there are break-out-the-KY-Jelly days."
In the Book of Useless Knowledge it is stated: "The chance to die after being kicked by a Donkey is actually far higher than dying during an Airplane chrash." (check global statistics) but RNG is that Mach Five Donkey Dive-Bomber that will take you out in the middle of a LAKE while you are celebrating your birthday. Don't screw with RNG man, 'cause she's a Craftsmen Powerdrill and you happen to fit her Phillip's Head.