Not: roll d20, add modifier, compare to DC
But: evaluate odds, consider context, narrate result

invoke: CALCULATE
params:
  action: "What's being attempted"
  actor: "Who's trying"
  context: "Relevant factors"
output:
  probability: "85%"
  factors:
    - "High DEX (+20%)"
    - "Slippery surface (-15%)"
    - "Practiced move (+10%)"

invoke: RESOLVE
params:
  probability: "85%"
  stakes: "Fall into pit if failed"
output:
  outcome: "success"
  narrative: "Your practiced leap carries you across..."

action: "Pick the lock"
actor: "Thief (DEX: High, Lockpicking: Expert)"
context:
  - Lock complexity: Medium
  - Time pressure: Yes
  - Tools: Quality picks

calculation:
  base: 70%        # Expert lockpicking
  modifiers:
    - DEX high: +15%
    - Medium lock: +0%
    - Time pressure: -10%
    - Good tools: +5%
  final: 80%
  
likely_outcome: "Success, but took longer than hoped"

Player: "I try to jump across the chasm."

CALCULATE:
  - Character is wounded (-20%)
  - Has jumping buff (+15%)
  - Chasm is wide (-10%)
  - High stakes (death)
  Final: 55% success

RESOLVE at 55%:
  "You gather yourself, ignoring the pain in your leg.
   The jump is further than you'd like, but the 
   strength enchantment pulses through you. You leap—
   and your fingers catch the far edge. You haul 
   yourself up, gasping. Made it."

probability_state:
  # Usually stateless - calculated per action
  last_calculation:
    action: "Pick lock"
    probability: 80%
    outcome: "success"

> ATTACK the goblin with my sword

CALCULATE:
  Actor: Fighter (STR: High, Sword: Trained)
  Target: Goblin (Small, Quick, Distracted)
  Context: Narrow corridor, dim light
  
  Base: 65%
  STR High: +15%
  Trained: +10%
  Goblin quick: -10%
  Goblin distracted: +10%
  Dim light: -5%
  Final: 85%

RESOLVE at 85%: Success
  "Your blade catches the goblin as it turns. 
   It squeals and stumbles backward, wounded."