RuneQuest Stats

Strength (STR)
A basic measure of muscular force. This is solely a measure of how massive and well-developed your muscles are, though it includes back strength and leg strength as well as upper body strength. Greater muscles does help your fatigue as well as your lifting and hitting. Fatigue is determined by your STR and CON, while damage is determined by your STR and SIZ.
Constitution (CON)
A measure of health and resilience. This is an abstraction of many factors, including stamina, disease resistance, speed of healing, and the accumulation of various injuries. CON is where most effects of aging are seen: generally -1 CON per 5 years over 25.
Size (SIZ)
This is a basic measure of height and build, corresponding roughly to your weight when in good condition. Size gives a longer reach and greater leverage and force in combat. However, it also makes it harder to hide and do agile moves. A bulkier physique will mean a higher SIZ. However, dieting and overeating are mostly separate effects which will not change your SIZ. i.e. An overweight man is not equivalent to a giant. Starvation will primarily reduce STR, while being overweight will primarily reduce DEX.
Intelligence (INT)
A measure of one's ability to think abstractly, and ability to concentrate on and memorize arbitrary information. Essentially, this is how well one would do in scholarly pursuits -- which is only a small subset of full intelligence. As a stat, it affects most skills, but it is easy to have high skills regardless of intelligence. INT increases with age: generally +1 per 5 years over 25.
Power (POW)
This is a measure of supernatural life force and magical power. This power has particular associations of magic in myths and sagas. Magically powerful characters have an aura about them that lends greater force to personal interactions. They are also more in tune with the world, which helps them notice things. However, they also attract attention even when it is not desired -- particularly supernatural attention.
Dexterity (DEX)
This is a measure of general hand-eye coordination, manual dexterity, balance, and speed. This affects nearly all physical skills. It should represent the lowest common denominator of these general qualities. Thus, someone who is particular skilled at handicrafts but otherwise unexceptional should take average DEX and buy up his Craft skills.
Appearance (APP)
A measure of physical attractiveness. Obviously, individual tastes differ, but there are many universals (at least among humans). This includes many subtleties of style, grooming, and grace. However, it does not include interaction: i.e. APP defines how attractive you are to look at in general (including if you were secretly spied upon), but actively courting someone's attraction is a skill.

Agility Skills

Boat (05)
This is skill in small watercraft such as canoes, skiffs, and rowboats. Characters may only be familiar with one or two types, but after a brief adjustment their boating skills should apply soon enough. Most boating can be done without a skill check, and skill 15 is sufficient for most operation. Higher skill is needed primarily for handling river rapids, whirlpools, and shoals. Skill also applies in chases, but this is also a function of sheer strength.
Climb (40)
This is basic skill at climbing. Active adults can all climb trees with low branches, steep slopes, and so forth. The more difficult the climb, the less distance is covered with each successful roll. Skill 50 and good health is sufficient to eventually climb most obstacles. Higher skill is primarily for doing so quickly, stealthily, or under adverse conditions. Marginal failures indicate only delay, being unable to find appropriate hand or foot holds. A critical failure indicates a fall of some sort. A Jump check should be made to see how bad a fall it was.
Dodge (05)
This is skill at dodging blows in melee, and secondarily at dodging thrown or missle weapons. A successful check completely avoids damage from a single attack, as long as the attack was not a critical success. A marginal failure mitigates the damage by 1 point. A critical failure is as if you hadn't dodged at all.
Jump (25)
This is skill at leaping for height and/or distance, as well as at landing nimbly. A successful Jump check is generally twice your height for a running broad jump. Halve that for failure. Also halve it for a standing jump.
Ride (05)
This is skill at riding horses, camels, and other animals. Unfamiliar types of animals will have a penalty at first, but after some exposure the character should soon be able to apply full skill. Riding a trained horse at a walk does not require a roll. Riding as a means of travel requires a minimum skill of 15, while 30 is sufficient for most situations. Higher skill is needed for speed, mounted combat, handling untrained or unruly mounts, or riding in difficult terrain.
Swim (15)
This is skill at swimming. Base skill of 15 is sufficient for treading water and dogpaddling in calm conditions. A roll is generally required for
Throw (25)
A palm-size object balanced for throwing can be thrown 1 yard for every STR point over the object's SIZ. Unbalanced objects (or creatures) can be throw 1 yard for every 3 STR over the object's SIZ.

Communication Skills

Fast Talk (05)
This is the basic skill of lying as well as skill in witty conversation and verbal persuasion. A successful roll means a convincing performance. A normal failure means that while smoothly spoken, the attempt was not neccessarily convincing beyond the true merits of what was said. Also, a keen listener could spot some telltale cues.
Orate (05)
This is skill at diplomatic, political, and/or persuasive speech. It includes both public speaking and personal interaction. While Fast Talk manipulates on the intellect, Orate appeals to emotions. It is also a skill in more long-term interactions, while Fast Talk is more immediate.
Sing (05)
This is the ability to sing pleasingly in both lyrics and tune, as well as knowledge of songs and music. Song almost always plays an important part in primitive cultures. A successful roll indicates an emotionally effective performance. A normal failure may be technically well-done, but is not a good performance.
Speak <Language> (05)
Skill in speaking your own or foreign languages. Skill of 30 is basic fluency: you can communicate readily, but have the accent of your upbringing and may get confused at specialized terms. Rolls are not usually called for.

Knowledge Skills

Animal Lore (05)
This is skill in understanding both wild and domesticated animals. This is the primary skill in training and caring for domesticated animals, and is a secondary skill in hunting and trapping.
Craft (10)
This is a set of many different skills of manual crafts. Each craft is generally treated as a separate skill, but most crafts start at the base of 10. Skill 30 is sufficient for reliably creating functional items in a fixed time. Higher skill is for producing masterwork items and/or working extraordinarily fast or under difficult conditions.
Evaluate (05)
This is skill in understanding the value of artifacts and goods, as well as general knowledge of economics and trade. A Craft or Lore skill can replace Evaluate for trade within that field. Thus, a jeweler (i.e. Craft: Jeweler) knows the value of gems and jewels, and a horse trainer (Animal Lore) knows the relative value of horses and livestock. Evaluate is skill in trading without specific knowledge.
First Aid (10)
This is practical skill in dealing with injuries. An attempt to treat injuries takes at least 5 combat rounds. A successful roll stops any bleeding and heals 1d3 hit points (double for a critical success).
Human Lore (05)
This is practical skill in understanding people, subsuming psychology and sociology.
Mineral Lore (05)
This is practical skill in understanding geology and soils. A small amount of skill is common for both farmers and miners.
Plants Lore (05)
This is practical skill in understanding both wild herbs and domesticated crops. It includes knowledge of what is edible as well as herbs for various purposes, and raising good crops.
World Lore (05)
This is practical skill in geography: knowledge of both local and distant places, landmarks, trails, and so forth. High skill indicates both detailed knowledge of your home terrain, and the ability to more quickly learn your way around new terrain.
Read/Write <Alphabet> (00)
This is knowledge of how to read and write. It is taken once for each alphabet: Latin and Runic. The Norse at points would write in either of these. Latin is usually favored for scholarly and religious purposes, but runes are still used for local records, histories, and so forth.
Shiphandling (05)
This is skill at operating a large ship -- essentially any craft for more than 3 or 4 people. It includes sail-setting, navigation, arranging watches, and all other practical details of running a ship.

Magic Skills

Magic skills are handled differently depending on the tradition of magic which one comes from. The details of these are described separately. Lagakin shamans have three general-purpose skills: Discorporate, Spirit Combat, Contacts. Runic sorcerers have a separate skill for each type of charm they know.

Manipulation Skills

Conceal (05)
This is skill at hiding things, from secreting a knife on your body to camouflaging a house.
Devise (05)
This is skill at understanding mechanical constructs, including how to invent and disassemble them. Assembling known designs is the Craft skill.
Sleight (05)
This is skill at manipulation of small objects, including pick-pocketing, juggling, and palming. It includes the art of misdirecting attention as well as smooth and quick handling.

Perception Skills

Listen (25)
This includes both actively listening for sounds and recognizing particular sounds in ordinary activity.
Scan (25)
This is primarily observing an area for movement, the skill of hunters and guards. It is a function of distance vision.
Search (25)
This is skill of finding details and objects within the immediate area.
Track (05)
This is skill in tracking, also used in covering up tracks. The difficulty of the tracks determines how far you get with each success.

Perception Skills

Hide (10)
This is essentially all means of hiding oneself from others. An important part of this is understanding what others can see -- it is much easier to hide if you know where the watcher's are. If the character is not moving and knows roughly where the watchers are, a success guarantees that she cannot be seen. A normal failure indicates you are more difficult to notice, requiring an additional Scan roll.
Sneak (10)
This is moving quietly and otherwise stealthily. As with Hide, perception of who you are hiding from is very useful for this. A successful roll means that you made no sound for a time (which depends on the terrain). A normal failure indicates that you made less sound than typical, requiring an additional Listen roll.