The mechanics are set on where success and failure happens, but when you roll the dice you vividly describe how the actions are carried out.Resolution Mechanics
-Roll a d20+modifiers to beat DC.
-Gain X successes before Y turns pass.
-If you fail 3 times in a row you are knocked out of the challenge
Character Creation
You are a murderhobo adventurer. Choose 6 skills from the list below to be Proficient in, and then choose 3 skills you are proficient in to be Focused in.
If you are not trained in a skill you are -4 on rolls to use it
Proficiency has a +0 bonus, removing the penalty for being untrained
Focused grants a +3 bonus to rolls.
You gain a modifier to ALL skills equal to your level
Skill List
Athletics
Acrobatics
Endurance
Insight
Perception
Thievery
Stealth
Apothecary
Bluff
Intimidate
Diplomacy
Religion
Arcana
Nature
Streetwise
History
Running a Challenge
The nature of the challenge determines how effective/limited each skill is.
Determine the effectiveness of each skill for the challenge
Perfect: The skill is highly appropriate and gains +2 when rolled.
Neutral: The skill works as normal without any modifiers
Bad: The skill is inappropriate for the challenge and suffers a -2 penalty to rolls.
Locked: Using this skill cannot add a success
Certain Skills may have additional effects when a success is achieved
-Limited: After X successes are achieved with this skill it becomes Locked
-Unlock: This skill's success changes the effectiveness of another skill, such as making a Locked skill now neutral or a Bad skill becomes Perfect.
-Save: This skill's success allows a KO'd player back into the challenge
-Extend: This skill's success adds another round of rolling to the skill challenge
DC's and level appropriateness
Here's a guide to setting DC's for challenges
Too Easy: DC= Character level +2
Very Easy: DC= Character level +5
Decent Challenge: DC= Character level +8
Evenly Matched: DC= Character level +10
Tough: DC= Character level +12
Very Tough: DC= Character level +15
Incredibly Tough: DC= Character level +18
Impossible: DC= Character level +20
If I were to cram this into a D&D4e inspired heartbreaker the math would probably be adjusted, but how does it stand as it is?
Building a challenge is basically the GM taking a list of the skills listed and marking off which skills will be perfect/neutral/bad/locked/limited/unlockers/savers/extenders.