GURPS Rules

GURPS stands for “Generic Universal RolePlaying System,” the RPG that these rules are condensed from. Why is it called that? Well . . .

“Generic.” GURPS starts with simple rules, and builds up to as much optional detail as you like. This abridged version presents the “core rules” that most GMs start with.

“Universal.” The basic rule system is designed to emphasize realism. It can fit any situation – fantasy or historical; past, present, or future.

“RolePlaying.” This is not just a “hackand-slash” game. The rules are written to make true roleplaying possible – and to encourage it. In GURPS, you pretend, for a little while, to be someone else.

“System.” Over 200 different books have been published for GURPS, in eight different languages (so far). It is one of the recognized standards for roleplaying, worldwide.

TLDR: Here is how to play GURPS in a nutshell.  Almost everything is a skill, or functions similarly to one.  The better you are at a skill, the higher your skill level.  In order to succeed at something, roll 3d6, and if the result is less than your skill level, you succeed.  Creating and improving your character is all point-buy, and there is no such thing as a "character level."  You earn points to spend on improving your character as you adventure. 

GURPS uses six-sided dice only. To figure combat damage (and several other things), the “dice+adds” system is used. If a weapon does “4d+2” damage, this is shorthand for “roll 4 dice and add 2 to the total.” Likewise, “3d-3” means “roll 3 dice and subtract 3 from the total.” If you see just “2d,” that means “roll two dice."

A “success roll” is a die roll made when you need to “test” one of your skills or abilities. Sometimes you roll; sometimes the GM rolls for you. For instance, you might test, or roll against, your Strength to stop a heavy door from closing.

What to Roll

Whenever a character attempts to perform an action (e.g., use a skill), roll three dice to determine the outcome. This is called a success roll. The task in question succeeds if the total rolled on the dice is less than or equal to the number that governs the action – most often a skill or an attribute. Otherwise, it fails. For example, if you are rolling against Strength, and your ST is 12, a roll of 12 or less succeeds. Thus, the higher the stat you are rolling against, the easier it is to make the roll.

Regardless of the score you are rolling against, a roll of 3 or 4 is always a success, while a roll of 17 or 18 is always a failure. In general, the player makes the die rolls for his character’s actions. However, the GM may always choose to roll the dice in secret – see When the GM Rolls, below.

When To Roll

To avoid bogging down the game in endless die rolls, the GM should only require a success roll if . . .

• A PC’s health, wealth, friends, reputation, or equipment are at risk. This includes chases, combat (even if the target is stationary and at point-blank range!), espionage, thievery, and similar “adventuring” activities.
• A PC stands to gain allies, information, new abilities, social standing, or wealth.

The GM should not require rolls for . . .

• Utterly trivial tasks, such as crossing the street, driving into town, feeding the dog, finding the corner store, or turning on the computer.
• Daily work at a mundane, nonadventuring job.

When the GM Rolls

There are two sets of circumstances under which the GM should roll for a PC and not let the player see the results:

1. When the character wouldn’t know for sure whether he had succeeded.

2. When the player shouldn’t know what’s going on

Modifiers

The rules often specify modifiers for certain success rolls. These bonuses and penalties affect the number you are rolling against – your “target number” – and not the total rolled on the dice. Bonuses always improve your odds, while penalties always reduce them.

For instance, when using the Lockpicking skill in the dark, the GM might tell you to roll at -5 for the attempt. If your Lockpicking skill is 9, you roll against 9 minus 5, or 4, in the dark.

A specific scenario might provide modifiers to allow for the relative ease or difficulty of a particular situation. For instance, an adventure might state that a lock is +10 to open due to the fact that it is primitive and clumsy. If your Lockpicking skill were 9, you would roll against 9 + 10, or 19. Since the highest roll possible on 3d is 18, it would seem that success is assured. Not quite – see Critical Success and Failure, below.

Modifiers are cumulative unless stated otherwise. For instance, if you tried to open that primitive lock in the dark, both modifiers would apply, and you would roll against 9 - 5 + 10, or 14.

Base Skill vs. Effective Skill

Your base skill is your actual level in a skill, as recorded on your character sheet. Your effective skill for a particular task is your base skill plus or minus any modifiers for that task. In the Lockpicking examples above, the base skill is 9 in all cases, while the effective skill is 4, 19, or 14. You may not attempt a success roll if your effective skill is less than 3 unless you are attempting a defense roll.

Degree of Success or Failure

Once you have calculated your effective skill by applying all the relevant modifiers to your base skill, roll 3d to determine the outcome. If the total rolled on the dice is less than or equal to your effective skill, you succeed, and the difference between your effective skill and your die roll is your margin of success.

Example: If you have effective skill 18 and roll a 12, you succeed; your margin of success is 6.

If you roll higher than your effective skill, you fail, and the difference between the die roll and your effective skill is your margin of failure.

Example: If you have effective skill 9 and roll a 12, you fail; your margin of failure is 3.

Many rules use margin of success or failure to calculate results that matter in play, so be sure to note it when you roll.

Critical Success

• A critical success is an especially good result.
• A roll of 3 or 4 is always a critical success.
• A roll of 5 is a critical success if your effective skill is 15+.
• A roll of 6 is a critical success if your effective skill is 16+.

When you roll a critical success, the GM determines what happens. It is always something good! The lower the roll, the better “bonus” he gives you.

Critical Failure

• A critical failure is an especially bad result.
• A roll of 18 is always a critical failure.
• A roll of 17 is a critical failure if your effective skill is 15 or less; otherwise, it is an ordinary failure.
• Any roll of 10 or more greater than your effective skill is a critical failure: 16 on a skill of 6, 15 on a skill of 5, and so on.

When you roll a critical failure, the GM determines what happens. It is always something bad – the higher the roll, the worse the result.

Repeated Attempts

Sometimes you only get one chance to do something (defuse a bomb, jump over a crevasse, remove an inflamed appendix, please the King with a song). Other times you can try over and over again until you succeed (pick a lock, catch a fish, analyze a poison). Still other times you will not know whether you succeeded or failed until it’s too late to try again (translate an old treasure map, order in a French restaurant, build a ship). Finally, there are times when you are injured by failure but can afford to fail a few times (climb a wall, impress a savage tribesman).

The GM must use common sense to distinguish among these cases, according to the exact situation in which the adventurers find themselves.

Contests

Sometimes a situation arises in which two characters must compare attributes, skills, or other traits to settle a competition. The one with the highest score doesn’t always win . . . but that’s the way to bet. A “Contest” is a quick way to handle such a competitive situation without playing it out in detail. In a Contest, each competitor attempts a success roll against the ability being tested – with all applicable modifiers – and then compares his result to his opponent’s. There are two different ways to make this comparison.

Quick Contest

A “Quick Contest” is a competition that is over in very little time – often in one second, perhaps even instantly. Examples include two enemies lunging for a gun or two knife throwers seeing who gets closer to the bull’s-eye.

Each competitor attempts his success roll. If one succeeds and the other fails, the winner is obvious. If both succeed, the winner is the one with the largest margin of success; if both fail, the winner is the one with the smallest margin of failure. A tie means nobody won (in the examples above, both fighters grabbed the weapon at once, or the knives hit the same distance from the bull’s-eye)

The amount by which the winner beat the loser, the margin of victory, is often important – success by 5 vs. failure by 5 generally means more than success by 2 vs. success by 1! The winner’s “margin of victory” is the difference between his margin of success and the loser’s margin of success if both succeeded, the sum of his margin of success and the loser’s margin of failure if he succeeded and the loser failed, or the difference between the loser’s margin of failure and his margin of failure if both failed.

Regular Contest

A “Regular Contest” is a slow competition with much give and take – for instance, arm wrestling.

Each character attempts his success roll. If one succeeds and the other fails, the winner is obvious. If both succeed or both fail, the competitors’ relative positions are unchanged and they roll again. Eventually, one character succeeds when the other fails. At this point, the one who made his roll is the winner.

The length of game time each attempt takes depends on the activity, and is up to the GM. In a combat situation, each attempt takes one second . . . but in a library-research contest, with the fate of the world hanging on who finds a certain obscure reference first, each attempt could represent days of time.

Heads up!  Reaction rolls may not actually be used extensively, especially when you're simply in a scene with another Player Character.  Good RP means factoring in the details when determining how a character should react to a situation.  When we want to leave it to chance, we'll use a reaction roll.  Otherwise, you can simply mention your reaction roll modifiers whenever they would seem relevant, skip the roll, and see if other characters react accordingly.  We don't want the dice to make someone play their character a certain way. 

When the PCs meet an NPC whose reaction to them is not predetermined (see below), the GM makes a “reaction roll” on 3d. The higher the roll, the better the reaction. The GM then plays the NPC according to the guidelines on the Reaction Table.

The GM should keep this roll secret from the players. They don’t know, for instance, whether that friendly-looking old farmer is giving them straight advice or sending them into a trap.

A reaction roll is not a success roll. There are three important differences:

1. There is no “target number” to roll against.

2. A high roll is good, not bad.

3. Reaction modifiers apply directly to the die roll. A reaction bonus is any factor that makes NPCs friendlier, while a reaction penalty is something that biases NPCs against the PCs.

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Reaction Table

Roll 3 dice and apply any reaction modifiers.

• 0 or less: Disastrous. The NPC hates the characters and will act in their worst interest. Nothing is out of the question: assault, betrayal, public ridicule, or ignoring a life-ordeath plea are all possible.
• 1 to 3: Very Bad. The NPC dislikes the characters and will act against them if it’s convenient to do so: attacking, offering grossly unfair terms in a transaction, and so on.
• 4 to 6: Bad. The NPC cares nothing for the characters and will act against them (as above), if he can profit by doing so.
• 7 to 9: Poor. The NPC is unimpressed. He may make threats, demand a huge bribe before offering aid, or something similar.
• 10 to 12: Neutral. The NPC ignores the characters as much as possible. He is totally uninterested. Transactions will go smoothly and routinely, as long as protocol is observed.
• 13 to 15: Good. The NPC likes the characters and will be helpful within normal, everyday limits. Reasonable requests will be granted.
• 16 to 18: Very Good. The NPC thinks highly of the characters and will be quite helpful and friendly, freely offering aid and favorable terms in most things.
• 19 or better: Excellent. The NPC is extremely impressed by the characters, and will act in their best interests at all times, within the limits of his own ability – perhaps even risking his life, wealth, or reputation.

Character Points

Character points are the “currency” of character creation. Anything that improves your abilities costs character points: you must spend points equal to the listed price of an ability to add that ability to your character sheet and use it in play. Anything that reduces your capabilities has a negative cost – that is, it gives you back some points. For instance, if you start with 125 points, buy 75 points of advantages, and take -15 points of disadvantages, you have 125 - 75 + 15 = 65 points remaining.

Starting Points The GM decides how many character points the player characters (PCs) – the heroes – start with. This depends on how capable he wants them to be.

Some example power levels, with suggested starting points:

Feeble (under 25 points): Small children, mindless thralls, zombies, etc.

Average (25-50 points): Ordinary folks, such as accountants and cab drivers.

Competent (50-75 points): Athletes, cops, wealthy gentry . . . anyone who would have a clear edge over “average” people on an adventure.

Exceptional (75-100 points): Star athletes, seasoned cops, etc.

Heroic (100-200 points): People at the realistic pinnacle of physical, mental, or social achievement; e.g., Navy SEALs, world-class scientists, and millionaires. Larger Than-Life (200-300 points): Leading roles in kung fu movies, fantasy novels, etc.

Legendary (300-500 points): Protagonists of epic poems and folklore.

This beginning point level is sometimes referred to as the power level of the campaign.

Disadvantage Limit

A disadvantage is anything with a negative cost, including low attributes, reduced social status, and all the specific disabilities listed under Disadvantages. In theory, you could keep adding disadvantages until you had enough points to buy whatever advantages and skills you wanted. In practice, most GMs will want to set a limit on the disadvantage points a PC may have. A good rule of thumb is to hold disadvantages to 50% of starting points – for instance, -75 points in a 150-point game.

For our game: we will be starting with 100 character points, with a disadvantage limit of 50.

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To read more about the different aspects and abilities of a character, head over to the following pages:

• Basic Attributes
• Secondary Characteristics
• Social Characteristics
• Advantages
• Disadvantages
• Skills

Character Improvement

At any time, the GM may award bonus character points for good play; these are the same kind of points you used to create your character. Bonus points are used to develop and improve your character. Record them as “unspent” on your character sheet. Then spend them the same way as during character creation, as follows:

To improve one of your basic attributes, you must spend character points equal to the point-cost difference between the old score and the new one. Note that improving basic attributes will also affect secondary characteristics!

Most advantages are inborn, and cannot be “bought” later on. Exceptions include Combat Reflexes and languages, which can be learned, and social advantages like Status, which can be earned (in some societies). To add an advantage, you must pay the appropriate character points.

Houserule: If you can make a case that your story arc supports adding a new advantage, you might be able to.  Advantages listed under recommended improvements for your race are almost always allowed.

A character may get rid of most beginning disadvantages by buying them off with points equal to the bonus earned when the disadvantage was taken, as long as the player and GM can agree on a logical explanation for this.

Earned character points can be used to increase your skills or add new ones. When you improve a skill, the cost is the difference between your current skill level and the cost of the new skill level.

Below are rules for common physical tasks of importance to adventurers. For tasks not listed here, make DX rolls for matters of precision and HT rolls for feats of endurance. To determine weight moved or work done, use Basic Lift. Movement speed should generally be proportional to Basic Move.

A lot of this section might be, in all honesty, more rules-heavy than we really need for this game, but it's here nonetheless.

Climbing

To climb anything more difficult than a ladder, roll against Climbing skill (p. 14). This defaults to DX-5. Modifiers to the roll depend on the difficulty of the climb (see below). In all cases, subtract your encumbrance level from your roll as well. Combat speed on the table below costs 1 FP per Climbing roll.

Make one roll to start the climb and another roll every five minutes. Any failure means you fall (see Falling, p. 32). If you secured yourself with a rope, you will fall only to the end of the rope unless you rolled a critical failure.

Hiking

Sustainable cross-country speed on foot depends on ground Move. Start with Basic Move and reduce it for encumbrance, injury, and exhaustion, as applicable. The distance in miles you can march in one day, under ideal conditions, equals 10xMove.

A successful roll against skill increases marching distance by 20%. Roll daily. A group led by someone with Leadership skill at 12+ may make a single roll against the group’s average Hiking skill. (Hiking defaults to HT-5 for those who have not studied it.) Success lets the entire group march 20% farther; failure means the whole group must forgo the bonus.

Once you know your ideal daily mileage, modify it for circumstances as follows:

• Very Bad: Deep snow, dense forest, jungle, mountains, soft sand, or swamp. x0.2.
  
• Bad: Broken ground (including streams), forest, or steep hills. x0.5.
• Average: Light forest or rolling hills ¥1.
  
• Good: Hard-packed desert or level plains. ¥1.25.

Adverse weather conditions – rain, snow, or ice – often reduce these values further.

Jumping

When you want to jump over something much smaller than you, the GM should say, “Okay, you jumped over it,” and get on with play. Such jumps succeed automatically. But when the obstacle seems really significant, or if the GM put it there as a deliberate hazard, use the following rules.

Jumping Distance

Your Basic Move determines jumping distance, as follows:

High Jump: (6xBasic Move)-10 inches. For example, a Basic Move of 6 lets you jump 26” straight up. For a running jump, add the number of yards you run to Basic Move in this formula. Maximum running high-jump height is twice standing highjump height.

Broad Jump: (2xBasic Move)- 3 feet. For example, a Basic Move of 6 lets you jump 9 feet from a standing start. For a running jump, add the number of yards you run to Basic Move in this formula. Maximum running broad-jump distance is twice standing broad-jump distance.

Lifting and Moving Things

Basic Lift governs the weight you can pick up and move. The GM may let multiple characters add their BL (not their ST) whenever it seems reasonable; e.g., to carry a stretcher or pull a wagon.

One-Handed Lift: 2xBL (takes two seconds).

Two-Handed Lift: 8xBL (takes four seconds).

Shove and Knock Over: 12xBL. Double this if you have a running start. The GM can also make allowances for precariously balanced objects, to make them easier to tilt.

Carry on Back: 15xBL. Thus, you can carry more than you can lift by yourself . . . but every second that your encumbrance is over 10¥BL (that is, Extra-Heavy encumbrance), you lose 1 FP.

Shift Slightly: Depending on your footing and the way you are braced, you could shift or rock 50xBL.

Running

Your running speed, or ground Move, is equal to your Basic Move score modified for encumbrance. Sprinting is all-out running. It is very fast, but also fatiguing. You can sprint if you run forward for two or more seconds. Add 20% to your Move after one second. For instance, with a Move of 7, you could sprint at 8.4 yards/second after running for one second at 7 yards/second.

If you need to run a long distance, you will want to pace yourself to avoid exhaustion. Paced running averages exactly half the sprinting speed calculated above.

After every 15 seconds of sprinting or every minute of paced running, roll against HT. On a failure, you lose 1 FP. Once you are reduced to less than 1/3 your FP, halve your Move for any kind of running.

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Swimming

Make a roll against Swimmingskill  any time you enter water over your head, and again every 5 minutes. Subtract twice your encumbrance level; add 3 if you entered the water intentionally. If you fail, lose 1 FP and roll again in 5 seconds, and so on until you reach 0 FP and drown, get rescued, or succeed at a roll. If you recover, roll again in 1 minute. If you succeed, go back to rolling every 5 minutes.

Land-dwellers such as humans have water Move equal to Basic Move/5 (round down), minimum 1 yard/second. After every minute of top-speed swimming, roll against the higher of HT or Swimming skill. On a failure, you lose 1 FP. Once you are reduced to less than 1/3 your FP, halve your water Move.

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Throwing

You can throw anything you can pick up – that is, anything with a weight of 8xBL or less. If the object you wish to throw is not already in your hands, you must take one or more Ready maneuvers to pick it up. See Lifting and Moving Things, above, for details.

Throwing an object during combat – whether as an attack or not – requires an Attack maneuver. You can throw objects that weigh up to 2xBL using one hand; heavier objects require a two-handed throw. Roll against DX-3 to hit a specific target, or against DX to lob something into a general area. Apply the usual modifiers for target size, speed, and distance. See also: Throwing, Knife Throwing, Spear Throwing, Axe/Mace Throwing.

The sourcebook goes into detail about how much you can throw, and how much damage it would do, but it's mathy and hopefully we'll never need it. 

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Sense Rolls

“Sense rolls” include Vision rolls, Hearing rolls, and Taste/Smell rolls. To notice something using a given sense, roll against your Perception score.

A successful Sense roll means you noticed something. That is often sufficient, but in some cases, the GM may require a second roll to understand what you have sensed; e.g., to realize that the “owl hoot” you heard is really an Indian warrior, or that the faint scent you noticed belongs to the flower of a man-eating plant. This roll is against IQ for details that anyone could figure out, or against an appropriate skill if the significance would be lost on anyone but an expert.

Vision

Make a Vision roll whenever it is important that you see something. When you try to spot something that is deliberately hidden, the GM may treat this roll as a Quick Contest against a concealment skill (Camouflage, Holdout, etc.), and may allow – or require – a skill such as Observation or Search to replace Perception for the roll.

Hearing

Make a Hearing roll whenever it is important that you hear a sound. The GM will often require a separate IQ roll to make out speech, especially in a foreign language. When you try to hear someone who is attempting to move silently, the GM may treat this roll as a Quick Contest against his Stealth skill. If you are actively listening for such activity, the GM may allow you to substitute Observation skill for Perception.

Taste/Smell

Taste and smell are two manifestations of the same sense. Make a Taste roll to notice a flavor, or a Smell roll to notice a scent.

Sneaking up on someone while they're sleeping

If the sneaky person succeeds on a Stealth roll, then the sleepy person stays asleep (modifiers for Silence apply).  If the sneaky person fails the Stealth roll, you need to succeed on a roll of Per-6 (typically hearing) to wake up. On a critical failure, the sleepy person wakes up with no roll. Combat Reflexes, Deep Sleeper, and Light Sleeper modify this. 

Influence Rolls

An “Influence roll” is a deliberate attempt to ensure a positive reaction from an NPC. A PC with an appropriate “Influence skill” can always elect to substitute an Influence roll for a regular reaction roll in suitable circumstances (GM’s decision).

Decide which Influence skill you are using from this list: Influence. Choose wisely! The GM may allow other skills to work as Influence skills in certain situations (e.g., Law skill, when dealing with a judge). Then roll a Quick Contest: your Influence skill vs. the subject’s Will.

If you win, you get a “Good” reaction from the NPC – “Very Good” if you used Sex Appeal. On any other outcome, the NPC resents your clumsy attempt at manipulation. This gives you a “Bad” reaction – “Very Bad” if you attempted intimidation. Exception: If you used Diplomacy, the GM will also make a regular reaction roll and use the better of the two reactions. Thus, Diplomacy is relatively safe . . .

Interactions between PCs

A lot of the game will be focused on interactions with other PCs.  You can make reaction rolls against each other if you wish, or you can simply take into account the characters' skill levels in various skills when you RP, in both the way you present your character, and in the way you have them react to others.  The numbers on your sheet, and the character that comes across in your post, should ideally be illustrations of each other. When making Influence rolls against other PCs, you should also compare applicable reaction modifiers, and add them as a bonus or penalty to the roll, as appropriate. 

Additionally, the first time during a scene that someone succeeds at an Influence roll against you, respond however you think it makes sense, and they gain Leverage on you.  If they attempt further Influence rolls on you in the scene, you can choose whether it makes sense to give them Leverage or not.  It's recommended, but not required if it seems like too much or doesn't make sense.

Will Rolls

When you are faced with a stressful situation or a distraction, the GM may require you to roll against your Will to stay focused. On a success, you may act normally. On a failure, you submit to the fear, give in to the pressure, are distracted from your task, etc.

Fright Checks

A Fright Check is a Will roll made to resist fear. Fright Checks can occur as often or as rarely as the GM wishes. In a horror campaign where ordinary people meet shockingly gruesome Things, Fright Checks might be very common! With only minor adaptation, the GM can use these rules for awe, confusion, etc. as well as fear

As a general rule, “ordinary” frightening things do not require Fright Checks. Fright Checks are for events so unusual and terrifying that they might stun or even permanently scar someone.

A Fright Check is subject to any number of modifiers, including ones derived from appropriate advantages or disadvantages, and the circumstances surrounding the roll.

If you've skimmed a few of the sections above, then you've gotten yourself a good start to understanding how to play GURPS.  Don't feel overwhelmed; we don't expect you to remember all the rules right from day 1.  The best way to learn how to play an RPG, is to just play the RPG.  When it comes down to it, just have your characters do what characters do, and when it feels like there should be a roll, we'll look for one together. 

Here are a few more pages you may eventually need when playing the game:

• Combat
• Injury, Illness, and Fatigue
• Magic
• Lore
• Leverage