Rolling the Dice
When you attempt something with a real chance of failure and a real consequence, you make an Action Roll. Root and Stem uses graduated dice: the size of the die you roll grows with your odds, and the result is graded on a five-point scale instead of a simple pass or fail.
How Your Die Is Chosen
Before you roll, compare your total bonus to the challenge. That ratio is your Skill-to-Challenge Ratio (SRC), a percentage from 0% to 100%. The bigger your SRC, the bigger the die — and the easier a clean success becomes.
| SRC | Die |
|---|---|
| 0% – 15% | d4 |
| 16% – 25% | d6 |
| 26% – 35% | d8 |
| 36% – 45% | d10 |
| 46% – 49% | d12 |
| 50% – 64% | d20 |
| 65% – 100% | d100 |
Smaller odds mean a smaller die, which is exactly the tension you want: a long shot rolls a d4, a confident expert rolls a d100.
The Five Tiers
Every roll lands on one of five tiers:
| Tier | Result |
|---|---|
| 1 | Critical Failure |
| 2 | Failure |
| 3 | Partial Success (success at a cost) |
| 4 | Success |
| 5 | Critical Success (Apex) |
You build the Final Value of your roll like this:
Final Value = Die Roll + PROF_MOD + GRACE (clamped) + flat bonuses
PROF_MOD is your proficiency — a silent floor that rides every roll and also feeds your SRC. GRACE is the dynamic Creation–Entropy meter (−10 to +10) that shifts as the scene unfolds. Where your Final Value lands on the die's tier table decides your outcome. Difficulty is expressed as a required tier: Trivial needs 2+, Easy and Standard need 3, Hard and Very Hard need 4, and Heroic or Nearly Impossible need 5.
Your Stats and Modifiers
Six Root Stats describe who you are — STR, DEX, CON, INT, WIS, CHA. At level 1 you have 15 points to spread across them (0–6 each), and each score's modifier is floor((score − 5) / 2).
From those scores grow six Stem Modifiers, the aptitude totals that feed your SRC:
| Stem | Made from |
|---|---|
| PHYS | STR + DEX + CON |
| PSY | INT + WIS |
| RSV | CON + DEX |
| MGC | INT + WIS + CHA |
| GUI | INT + DEX + CHA |
| PROF | static, never decreases |
Pick the relevant Root Stat and Stem Modifier for the action, add any skill bonus and your PROF_MOD, and you have your Total Roll Bonus — the number that becomes your SRC.
Saves and Contested Rolls
A save is a graduated roll you make to resist something happening to you — a Luck Save uses the next die tier up and a bounded target so pure chance stays fair at every level. See the Core and The Roll chapter of the rules for the full Luck Save math.
In a contested roll, two sides work directly against each other — sneaking versus a guard's eye, a lie versus a sharp read. Both of you roll, and the higher Final Value wins. Ties go to the defender.