Training in a skill means that you have some combination of formal instruction, practical experience, and natural aptitude using that skill. When you select a skill to be trained in, you gain a permanent +5 bonus to that skill. You can’t gain training in a skill more than once. The entry for your class tells you how many skills you’re trained in and what skills you can choose at 1st level. You can take the Skill Training feat to gain training in a skill even if it’s not on your class skill list. Some multiclass feats also give skill training.
Using Skills
When you use a skill, you make a skill check. This check represents your training, your natural talent (your ability modifier), your overall experience (one-half your level), other applicable factors (relevant bonuses), and sheer luck (a die roll). The DM tells you if a skill check is appropriate in a given situation or directs you to make a check if circumstances call for one.
Skill Check Bonuses: When you create your character, you should determine your base skill check bonus for each skill you know. Your base skill check bonus for a skill includes the following:
✦ One-half your level
✦ Your ability score modifier (each skill is based on one of your ability scores)
✦ A +5 bonus if you’re trained in the skill In addition, some or all of the following factors might apply to your base skill check bonus:
✦ Armor check penalty, if you’re wearing some kinds of armor (see Chapter 7) and making a check using Strength, Dexterity, or Constitution as the key ability
✦ Racial or feat bonuses
✦ An item bonus from a magic item
✦ A power bonus
✦ Any untyped bonus that might apply
Skill Check: To make a skill check, roll 1d20 and add the following:
✦ Your base skill check bonus with the skill
✦ All situational modifiers that apply
✦ Bonuses and penalties from powers affecting you
The total is your check result.
Difficulty Class: When you make skill checks, high results are best. You’re always trying to meet or beat a certain number. Often, that’s a fixed number, called a Difficulty Class (DC). The DC depends on what you’re trying to accomplish and is ultimately set by the Dungeon Master. The skill entries in this chapter give sample DCs for each skill. The DM sets the DCs for specific situations based on level, conditions, and circumstances, as detailed in the Dungeon Master’s Guide. All DCs assume acting in situations that are far from mundane; the DM should call for checks only in dramatic situations.
Opposed Checks: Sometimes, you make a skill check as a test of your skill in one area against another character’s skill in the same area or in a different one. When you use Stealth, for example, you’re testing your ability to hide against someone else’s ability to spot hidden things (the Perception skill). These skill contests are called opposed checks. When you make an opposed check, both characters roll, and the higher check result wins. If there’s a tie, the character with the higher check modifier wins. If it’s still a tie, both sides roll again to break the tie.
Checks without Rolls: In some situations, luck does not affect whether you succeed or fail. In a calm environment (outside an encounter), when dealing with a mundane task, you can rely on sheer ability to achieve results.
Take 10: When you’re not in a rush, not being threatened or distracted (when you’re outside an encounter), and when you’re dealing with a mundane task, you can choose to take 10. Instead of rolling a d20, determine your skill check result as if you had rolled the average (10). When you take 10, your result equals your skill modifiers (including one-half your level) + 10. For mundane tasks, taking 10 usually results in a success.
Passive Checks: When you’re not actively using a skill, you’re assumed to be taking 10 for any opposed checks using that skill. Passive checks are most commonly used for Perception checks and Insight checks, but the DM might also use your passive check result with skills such as Arcana or Dungeoneering to decide how much to tell you about a monster at the start of an encounter. For example, if you’re walking through an area you expect to be safe and thus aren’t actively looking around for danger, you’re taking 10 on your Perception check to notice hidden objects or enemies. If your Perception check is high enough, or a creature rolls poorly on its Stealth check, you might notice the creature even if you aren’t actively looking for it.
Cooperation: In some situations, you and your allies can work together to use a skill; your allies can help you make a skill check by making a check themselves. Each ally who gets a result of 10 or higher gives you a +2 bonus to your check. Up to four allies can help you, for a maximum bonus of +8. If you have a choice, let the character in your group who has the highest base skill check bonus take the lead, while the other characters cooperate to give bonuses to the check.
Skill Challenges: A skill challenge is an encounter in which your skills, rather than your combat abilities, take center stage. In contrast to an obstacle that requires one successful skill check, a skill challenge is a complex situation in which you must make several successful checks, often using a variety of skills, before you can claim success in the encounter. In one skill challenge, you might use a Diplomacy check to entreat a duke to send soldiers into a mountain pass, a History check to remind him what happened when his ancestors neglected the pass’s defense, and an Insight check to realize that having your fighter companion lean on the duke with an Intimidate check wouldn’t help your cause. In another skill challenge, you might use Nature checks and Perception checks to track cultists through a jungle, a Religion check to predict a likely spot for their hidden temple, and an Endurance check to fight off the effects of illness and exhaustion over the course of days in the jungle. Whatever the details of a skill challenge, the basic structure of a skill challenge is straightforward. Your goal is to accumulate a specific number of victories (usually in the form of successful skill checks) before you get too many defeats (failed checks). It’s up to you to think of ways you can use your skills to meet the challenges you face.
Knowledge Skills
Some skills deal with knowledge about a particular topic: Arcana, Dungeoneering, History, Nature, and Religion. You can use such a skill to remember a useful bit of information in its field of knowledge or to recognize a clue related to it. You can also use such a skill to identify certain kinds of monsters, as noted in a skill’s description. The check DC increases based on the specific topic and how common the knowledge is. The check DC increases based on the specific topic and how common the knowledge is. Sometimes your DM might decide that the information you seek is available only to characters trained in an appropriate knowledge skill.
Paragon and Epic Tiers: If the knowledge pertains to the paragon tier or the epic tier, the DC increases as shown on the tables later in this section. Knowledge Checks Regardless of the knowledge skill you’re using, refer to the rules here when making a knowledge check. Common Knowledge: This includes the kind of general information that is commonly known about a given topic.
Expert Knowledge: This includes the kind of specialized information that only an expert in the field of study could possibly know.
Master Knowledge: This includes the kind of esoteric information that only a master in the field of study could possibly know.
Knowledge Skill: No action required—either you know the answer or you don’t.
✦ DC: See the table.
✦ Success: You recall a useful bit of information in your field of knowledge or recognize a clue related to it.
✦ Failure: You don’t recall any pertinent information. The DM might allow you to make a new check if further information comes to light.
| Level of Knowledge | DC |
|---|---|
| Common | 10 |
| Expert | 20 |
| Master | 25 |
| Paragon tier | +5 |
| Epic tier | +10 |
Monster Knowledge Checks: Regardless of the knowledge skill you’re using, refer to the rules here when making a check to identify a monster.
Monster Knowledge: No action required—either you know the answer or you don’t.
✦ DC: See the table.
✦ Success: You identify a creature as well as its type, typical temperament, and keywords. Higher results give you information about the creature’s powers, resistances, and vulnerabilities.
✦ Failure: You don’t recall any pertinent information. The DM might allow you to make a new check if further information comes to light.
| Monster Knowledge | DC |
|---|---|
| Name, type, and keywords | 15 |
| Powers | 20 |
| Resistances and vulnerabilities | 25 |
| Paragon tier creature | +5 |
| Epic tier creature | +10 |
Skill Descriptions
The first line of a skill description shows the name of the skill, followed by the key ability for that skill. You use the ability modifier for that ability score to figure out your base skill check bonus. For skills based on Strength, Constitution, and Dexterity, the description includes a reminder that your armor check penalty applies to that skill. The skill description explains the different ways you can use the skill and provides typical DCs. Each description also specifies what kind of action is required to use the skill.