Article Header Image
Skill DCs
Design & Development
By Stephen Schubert

We continually evaluate the tools we’ve put into the game. As we design and develop rules and mechanics, we base some of the work on underlying assumptions regarding how we expect players to advance and improve their characters through their choices of mechanical elements such as feats and items. A short time ago, we evaluated the DCs for the skills subsystem and made some adjustments to the rate at which DCs scale with level. These tables appear on page 126 of the Rules Compendium as well as on the DM Screen available in the DM Kit.

If you compare the new values to the DCs from the Dungeon Master’s Guide and DMG 2, you’ll notice that the DCs are higher across the board. You'll also notice that Hard DC entries scale faster than Easy and Moderate DCs by level. Finally, the new skill DC table has an entry for each level instead of grouping levels into bands of three. These changes are far from arbitrary, as you’ll see.

Early on, we divided checks into Hard, Medium, and Easy, but we didn’t do a good job of telling DMs which one to use in a situation. We needed a system that would not only guide the DM on when to use a particular check but also describe the sorts of characters that would be attempting these checks.

The first step when evaluating the DCs was to determine what those DC categories truly represent. Then we describe our archetypical character who fits that category and determine the typical skill bonus that character might have. Finally, we set DCs based on a curve of expected values that would provide a reasonable challenge at each level—we define reasonable challenge as a d20 roll that is successful around 65% of the time (you need to roll 8+ on the die).

DIFFICULTY CLASS BY LEVEL
Level Easy Moderate Hard Level Easy Moderate Hard
1 8 12 19 16 16 22 31
2 9 13 20 17 16 23 31
3 9 13 21 18 17 23 32
4 10 14 21 19 17 24 33
5 10 15 22 20 18 25 34
6 11 15 23 21 19 26 35
7 11 16 23 22 20 27 36
8 12 16 24 23 20 27 37
9 12 17 25 24 21 28 37
10 13 18 26 25 21 29 38
11 13 19 27 26 22 29 39
12 14 20 28 27 22 30 39
13 14 20 29 28 23 30 40
14 15 21 29 29 23 31 41
15 15 22 30 30 24 32 42

Easy: The action involved isn’t trivial but is still pretty simple. These are the simplest checks and should represent a reasonable challenge for characters that have no training in the skill (an untrained character). An untrained character is typically adding half his level to the skill and probably doesn’t have an ability score that helps him out. He might get another +1 by Epic tier, since all his ability modifiers have increased by 21st level. Trained characters have little risk of failure, and expert characters are nearly guaranteed success. These are the DCs that we suggest DMs should use when every character in the party is expected to make the check or for group checks (where half the PCs must succeed on the roll to earn a success for the group).

Moderate: A moderate check requires a bit of training or innate ability, or a bit of luck. These checks are aimed at skilled characters who have training in the skill, though there are other options for getting a similar skill modifier, such as having a high ability score (18+) in the skill’s key ability or combining a racial bonus and a moderate (14+) ability score. These DCs scale a little faster than easy DCs, which accounts for ability score increases or adding a feat or path feature if the key ability isn’t your primary or secondary class stat. These DCs are the standard difficulty for a skill check in a skill challenge.

Hard: These checks are designed to test characters who are even more focused on the particular skill, though there might still be some chance of failure even for these expert characters. Without additional assistance (such as a power bonus or another character’s aid), the expert PC will succeed against these DCs around two out of three times. The expert PC typically has training in the skill, and his or her primary ability score is the skill’s key ability (or secondary ability score along with a skill focus feat or racial bonus). As the character increases in level, we expect feat and item selection to provide an extra boost along the way, as well as ability score increases. This DC is a good choice to really challenge a focused PC, though it’s also a good DC to use for repeated successes with a single skill in a skill challenge (once the first, moderate attempt is successful).

All-In: As we identified these character archetypes, we also noted a fourth sort of PC—the “all-in” character. This guy takes every possible advantage toward maximizing a particular skill. He has feats, a racial bonus, starts with a 20 in the primary modifier, is trained in the skill, and searches out magic items that further advance his skill. Even with our now-higher Hard DC scale, this character is nearly guaranteed success. But it’s also difficult to get bonuses that high for more than one or two skills. Rather than push the Hard DCs out of reach of typical characters, we recognize that those characters exist and will be really good at their chosen vocation. If the DM is doing his job (and we’ve given even more tools to help with that), then that character will have his moments to shine but will also face many challenges that can't be tackled with his maxed-out skill.

These new DCs form the backbone for our skill challenges and for other skill-related rolls throughout the game. For example, escape DCs for monsters or traps can be set based on the sorts of characters we expect should have a chance.

We hope this sheds some light on the method behind our madness. Be sure to check out Rules Compendium for an in-depth look at setting up skill checks and challenges in your game!


About the Author

Stephen Schubert is a game developer for Wizards of the Coast, and is the Development Manager for RPGs and the Dungeons & Dragons game. He has provided development and design work for many 4th Edition D&D products, including the Monster Manual and Player’s Handbook series, and the upcoming release of Gamma World.