Why one solved challenge changes XP, difficulty and streak separately
After a correct solution, several progress indicators may change. Each one answers a different question, and the same XP must not be counted twice.
DoesItHold Editorial · · reviewed · progression-pipeline-001
Direct answer
The challenge difficulty determines one XP award for each relevant skill. That award updates the skill level. Adaptive difficulty, the daily streak and achievements then observe the result separately without granting the same XP again.
A difficulty-3 challenge awards 140 XP. A level-1 skill needs 100 XP, so it moves to level 2 and carries 40 XP toward the next threshold of round(100 × 2^1.5) = 283.
The same solution may also keep today's streak and unlock a milestone. Those changes recognize practice, but they do not add the 140 XP a second time. Keeping the signals separate lets the learner understand why each number moved.
- Solveone accepted challenge result
- Inferidentify the relevant skills
- Awardapply the difficulty XP once
- Adaptchoose the next difficulty separately
Minimal example
Scrollable code region
awardXp(skill, 140)
adjustDifficulty(skill, xpGained: 140)awardXpOnce(skill, 140)
adjustDifficulty(skill, solved: true)What changes: A difficulty-3 solution adds 140 XP to each inferred skill exactly once; streak and achievements observe the result but do not duplicate it.
Debugging method
Follow one accepted solution through four questions: which skills apply, how much XP each receives, what difficulty comes next and whether the result advances a streak or achievement.
- Verify that difficulties 1–5 map to 60/100/140/180/220 XP.
- Submit one solution and confirm that each relevant skill changes once.
- Reach skill level 5 and confirm that progress displays 100%.
- Confirm that the weekly board uses only solutions finalized by the server.
- Verify that changing local progress cannot alter public position.
Common wrong fix
Awarding XP again while choosing adaptive difficulty duplicates progress. Treating the weekly solved count as XP also gives one number two incompatible meanings.
Limits and edge cases
The selected skills are a product classification, not a complete account of everything learned. Sync occurs when available, so a pending local update may take time to appear on another device.