D20 Mechanic: Skills

Important Note: This skills revamp will be effective once all currently running games are ended. This notice was written 16/03/05.

Skills have always been something of a thorny issue in the d20 System. In Trinity d20, we utilize a system that is a conglomerate of a number of different solutions to the problem, with the goal being to reduce complexity and number of skills while retaining a robust skill system that can handle many different situations, as well as ensure that the feel of the core setting is maintained.

This section will give an overview of how skills function, the master skill list, and skill descriptions.

Overview

Skills represent some of the most basic and yet most fundamental abilities your character possesses. As your character advances in level, he can gain new skills and improve his existing skills dramatically. This section describes each skill, including common uses and typical modifiers. Characters can sometimes use skills for purposes other than those noted here, at the GM's discretion.

Acquiring Skills

Each level, your character gains a number of skill ranks dependent upon your class plus your Intelligence modifier. Investing a rank in a skill represents a measure of training in that skill. You can never have more ranks in a skill than your character level.

Skill Checks

Skill Check Bonuses
Level	BAB
Untrained	1d20 + ability modifier + racial modifier
Untrained Class Skill	1d20 + ability modifier + racial modifier + item bonus
Trained	1d20 + skill ranks + ability modifier + racial modifier + item bonus
Trained Class Skill	1d20 + 3 + skill ranks + ability modifier + racial modifier + item bonus

When your character uses a skill, he isn't guaranteed success. In order to determine success, whenever you attempt to use a skill, you must make a skill check.

Each skill rank grants a +1 bonus on checks made using that skill. When you make a skill check, you roll 1d20 and then add your ranks and the appropriate ability score modifier to the result of this check. If the skill you're using is a class skill (and you have invested ranks into that skill), you gain a +3 bonus on the check. If you are not trained in the skill (and if the skill may be used untrained), you may still attempt the skill, but you use only the bonus (or penalty) provided by the associated ability score modifier to modify the check. Skills can be further modified by a wide variety of sources—by your race, by a class ability, by equipment, by spell effects or magic items, and so on. See the table on the right for how to make a skill check.

If the result of your skill check is equal to or greater than the difficulty class (or DC) of the task you are attempting to accomplish, you succeed. If it is less than the DC, you fail. Some tasks have varying levels of success and failure depending on how much your check is above or below the required DC. Some skill checks are opposed by the target's skill check. When making an opposed skill check, the attempt is successful if your check result exceeds the result of the target.

Some items indicate that they are tools, with a listed skill or set of skills; in that instance, the item provides your attunement bonus as an item bonus to the skill check. If you are using a skill in which you have no ranks and is not a class skill, tools provide no bonus: with neither the background necessary to understand the skill nor training in the skill itself, additional tools only further complicate things, and are as likely to hinder as they are to help.

Active vs. Secret vs. Passive Skill Checks

Each skill check is defined in its description as either “active,” “secret,” or “passive.” Active skill checks represent the character intentionally doing something that quickly reveals failure (e.g. trying to leap over a wide crevasse), while secret skill checks represent him deliberately doing something with which failure isn’t immediately evident (e.g. attempting to influence someone), and passive skill checks represent him doing something subconsciously (e.g. noticing someone sneaking up on him).

When a character makes an active skill check, the player rolls the die to determine success, and the result is therefore obvious to him. He may gain a synergy bonus and can spend action points to improve the result. Further, an active skill check always requires a set amount of time to complete, as noted in the skill description. Finally, the character may have the option to “take 10” or “take 20” with an active skill check, as defined in the skill description.

When a character makes a secret skill check, the GM rolls the die to determine success, and the player is not informed of the result until and unless it becomes obvious (when a presumably sabotaged item is found to function properly, for instance). The character may gain a synergy bonus with a secret check. Further, a character may spend action points to improve a secret check result, but does so at his own risk, as he isn’t aware of the result before he improves it. If a secret check results in a threat, the GM is obliged to ask whether the character wants to activate it. Finally, like an active check, every secret check requires a set time to complete, and the character may have the option to “take 10” or “take 20,” as defined in the skill description.

When a character makes a passive skill check, the GM rolls the die to determine success, and the player is not informed of the result unless its success informs him of something (depending upon the GM, the character may not even realize that a failed check, or a check that provides no information, has occurred). The character may not spend action points to improve a passive skill check result, though some specific passive checks allow for critical successes (in which case, the GM will ask the character if he wishes to activate any threat rolled). The character never gains a synergy bonus from other skills when making a passive skill check. Further, passive skill checks are commonly, but not always, free actions (taking no time to perform and happening as a matter of course). Finally, unless the GM or a rule states otherwise, the character may not “take 10” or “take 20” with a passive skill check.

Taking 10 and Taking 20

Sometimes a character doesn’t want to chance failure so he takes his time. In this case he can “take 10,” which requires twice the normal time. He does not roll 1d20 when making the skill check; instead, his result is calculated as if he’d rolled a natural 10.

Example: Lorelei has an Acrobatics skill bonus of +8 and faces a jump with a DC of 15. She chooses to take twice as long to set her result to 18 and automatically succeed.

Alternately, a character might have all the time in the world and want to take advantage of it. In this case he can “take 20,” which requires twenty times the normal time. As with taking 10 there is no roll; the result is calculated as if he’d rolled a natural 20.

Example: Lorelei has a meager Impress skill bonus of +4 when she finds herself fortuitously snowed in at a prince’s home. She decides to take her time wooing him, taking 20 for a total result of 24. With any luck it’s high enough to turn his head.

In both cases there was no roll, so the character may not spend an action point to improve the result. Also, a character taking 10 or 20 may not score a threat nor be activated as a critical success.

A character may not take 10 or 20 when distracted, endangered, or possesses the stress status, nor may he do so when the GM determines that the element of chance is unavoidable. This option is also unavailable when making opposed, cooperative, and team checks (see below).

Multitasking

Sometimes a character must split his attention between multiple skill attempts - stabilizing a wounded friend while balancing on a precarious surface, for instance, or scanning a house for clues while listening for signs that the owner is lying to him. A character may split his attention between no more than two skill checks at a time and the GM must determine that any combination of skill checks is plausible. When multi-tasking, a character suffers a -5 penalty with both checks and his error range with each increases by 2.

Special Skill Results

Every skill check has an error range and a threat range, which are natural die results that trigger special skill results. Unless otherwise specified, a skill check has an error range of 1 and a threat range of 20, though character options, gear choices, and other effects may modify these base values. Bonuses expand the range of natural die rolls that trigger an error or threat, and penalties scale them back. Modifiers may not eliminate error and threat ranges.

Your Luck ability score impacts these ranges. If you have a positive Luck modifier, you increase your threat range by your bonus; if you have a negative Luck modifier, you increase your error range by your penalty.

Example: A character’s error range with a particular skill check increases by 2 and his threat range increases by 1. Unless other modifiers are in play, the check has an error range of 1–3 and a threat range of 19–20.

Example: A character has a Luck of 18. His base error range is 1, while his base threat range is 16-20; meanwhile, a character with a Luck of 7 has a base error range of 1-3, and a base threat range of 20.

Threats and Critical Successes

When a skill check succeeds and the character rolls a natural number within his threat range (an actual roll of the number on a d20), he scores a threat - a potential critical success. To gain the benefits of a critical success, the character simply spends 1 or more action points as listed in the skill description. No more than 4 action points may be spent to activate any critical success. When no cost is listed a character only needs to spend 1 action point to gain the benefit.

In some instances, the GM may see fit to apply alternate effects of his own.

Errors and Critical Failures

When a skill check fails and the character rolls a natural number within his error range (an actual roll of the number on a d20), or when a skill result is negative, the character suffers an error - a potential critical failure. He only suffers the effects of the critical failure, however, if his opponent - commonly the GM - spends 1 or more action points as listed in the skill description. No more than 4 action points may be spent to activate any critical failure. When no cost is listed, the opponent only needs to spend 1 action point to trigger the effect.

Critical failures are generally left to the GM’s discretion, though some skills may detail what occurs in the event of a critical failure.

Opposed Checks

When a character competes against someone else with a skill, he makes an “opposed check.” All involved make a standard skill check with the most relevant skill (e.g. Athletics for everyone in a foot race, Bluff for a lying character and Sense Motive for the listener, etc.), and the character with the highest result wins. Equal results tie unless this provides no clear result, in which case the winner is the character with the highest skill bonus. If this still ties, a random die roll determines the winner.

Cooperative Checks

When multiple characters work together to perform one task, the GM may ask for a “cooperative check.” In this case, one character performing the task must be chosen as the leader of the attempt. Each other character is called a helper. Determine all characters involved in a cooperative check and their roles in the task before rolling any dice.

First, the leader makes the skill check relevant to the task, generating the base check result.

Then, each helper makes the same skill check with a DC determined as follows.

• If the skill check has a set DC, each helper’s DC is 15.
• If the skill check has no set DC, each helper’s DC is equal to the leader’s check result minus 10 (minimum 15).

The leader gains a synergy bonus to his check result equal to the number of successful helpers (to a maximum +5 bonus per check, no matter how many helpers are involved). For each helper who scores a critical success, the leader gains an additional +1 bonus with his check result (this bonus is unnamed and can exceed the +5 limit).

If even one helper’s skill check results in a critical failure, the entire task is ruined and must be started again. The leader’s final skill check result - after all helper bonuses are applied - determines the cooperative check’s outcome. Two additional restrictions: first, only so many characters may work together to perform each check, as shown in each skill description; second, when making a cooperative check, neither the leader nor any helper may take 10 or take 20.

Team Checks

Sometimes several characters perform a single task together and individual success is irrelevant - when Bluffing, for example, even one failure can expose everyone involved. Other times several characters making the same check, or even a cooperative check, unfairly tips the odds in the characters’ favor (even a few characters can practically ensure success with Notice or Search, for instance). In either of these cases the group should make a “team check.” This works like a standard skill check, except that only one character makes the check for the entire team.

• If every member of the team must succeed to reap the benefit (e.g. the Bluff), the character with the lowest skill bonus makes the check.
• If only one character must succeed for the entire team to reap the benefit (e.g. the patrol), the character with the highest skill bonus makes the check. When two or more characters qualify, the team chooses which makes the check.

Knowledge Checks

Knowledge Checks
Obscurity	DC
Common knowledge (known by at least a substantial minority of people)	15
Uncommon knowledge (known by at least a minority of people in most areas)	20
Rare knowledge (known by very few people in several areas)	25
Obscure knowledge (known by at most a small minority throughout the world)	30
Forgotten knowledge (known by almost no one living)	35

Character knowledge differs from player knowledge and what a character knows can often mean the difference between victory and defeat, or life and death. When a character’s knowledge is in question he makes a “Knowledge check.” The player rolls 1d20 and adds his Int modifier + the total number of Studies he knows. He has the knowledge in question if his result beats the DC listed on Table: Knowledge Checks.

In standard d20, the Knowledge skill exists as a "catch-all" category, with a number of cascading skills below it that vary in utility. Rather than force characters to devote skill points to Knowledge skills, when it's entirely possible that a variety of different types of knowledge could reveal the same information, Knowledge is now a special type of skill check.

Each skill has a small section indicating different sorts of knowledge that comes with the territory of being trained in the skill. In addition, your Studies (this needs a link to somewhere, if we're using this mechanic) impact how much you know, with the idea being that the more areas you've invested time and effort into knowing about, the more your "general knowledge" improves.

You can choose to make a Knowledge check, or be asked by the GM to make a Knowledge check; in either instance, confirm with the GM what skill, if any, is applicable. To make the check, roll 1d20 + your Intelligence modifier + the number of Studies you have + 3 if you have at least one rank in a relevant skill, if any. The result of your check is compared to the DCs listed on Table: Knowledge Checks.

If you have a Study that is pertinent to the Knowledge check, you will most likely gain slightly more pertinent information (if you have a relevant study, you may need to remind the GM that you do).