Munchkins is designed to be a "lite" system. That means that the mechanics are designed to be quick and fast, not hyper-realistic or interesting in and of themselves.

Munchkins' system is designed around an ordered series of ranks,

All stats have a rating, usually between Poor and Great. To "test" an action, roll a single normal (six-sided) die, and compare it to this table:

A "miserable" automatically fails at anything that was worth rolling for in the first place. A "Remarkable" is sufficient to achieve anything that Munchkins are even theoretically capable of (which, it should be pointed out, excludes a great many things that humans take for granted). The GM should generally decide where, between those extremes, any given feat falls. In general, a Good or better result will succeed at most reasonable results, and a Fair may be sufficient if the task is reasonably mundane.

Opposed Skills

When two Munchkins (or a Munchkin and anything else) are competing in something, each of them rolls their appropriate stat (note they might be different stats. For example, if Joe Munchkin is trying to find Fred Munchkin, Joe Munchkin will roll Do Stuff while Fred Munchkin will roll Hide). The better result wins.

Hitting things is resolved as an opposed skill test between the Hit Munchkins attribute and the Scamper attribute. In the unlikely event that a Munchkin has the faintest possibility of harming something else, the Munchkin can use his Do Stuff attribute in place of the "Hit Munchkins" attribute.

Damage is rolled on this table, using the Hurt Munchkins stat:

The GM will apply damage from a Munchkin attack on a case-by-case basis (or GFP's may look under "Advanced Mechanics).

Creating your Munchkin

Munchkins are defined by 5 stats:

Hide

This stat defines a Munchkin's skill at hiding and sneaking around. It is vitally important for dealing with the many creatures who can effortlessly end a Munchkin's life.

Scramble

This stat defines how fast a Munchkin can move, and how good he is at avoiding getting hit. Highly important for those fast breaks across the kitchen floor.

Climb

You wouldn't think that Climbing would rate a stat of its own, until you consider that a Munchkin is 2" tall in a house built for people who average greater than 66" in height. Practically everything needs to be climbed.

Interpret Glowy Box

A Munchkin's status among his peers is relative to his skill at passing off his own interpretations of the Glowy Box's pronouncements as the correct ones. Whenever you and somebody else have different ideas of what the Glowy Box is telling you to do, roll your skills against each other. The loser bows to the winner's interpretation. Needless to say, having a high Interpret Glowy Box score is a good way to get your friends killed.

Do Other Stuff

Everything else a Munchkin might possibly be capable of is covered by the Do Other Stuff stat. While this may seem like an exceptionally useful stat, you should consider that Munchkins aren't really even theoretically capable of all that much.

You may either assign one Great, three Fairs, and one Poor amongst your stats, or two Goods, two Fairs, and one Poor. Then give your Munchkin a name (something short and descriptive is probably best), an appropriately surly personality, and you're ready to play!

Sample Munchkins

Runt:

Hide: Good
Scramble: Fair
Climb: Fair
Interpret Glowy Box: Good
Do Other Stuff: Poor

Speedy:

Hide: Fair
Scramble: Great
Climb: Fair
Interpret Glowy Box: Poor
Do Other Stuff: Fair

Stats for Non-Munchkins