What this is
Most build content tells you what to make. This tells you how to decide — where damage comes from, which of your statistics is starved, whether an item is an upgrade, and when a character is finished.
The end state is constructive independence: looking at a character you made yourself and knowing what to change next, without consulting anyone.
Two rules hold across every lesson. Arithmetic stays at one step — the kind done on paper or in your head. And no lesson hands over a build, because a finished build is precisely the thing that would short-circuit the skill being taught.
Lessons
| # | Lesson | Covers |
|---|---|---|
| 1 | The Three Questions | Relative change, proportion of a whole, comparison. Open practice on all three. |
| 2 | How a Hit Is Built | The six layers. Increased against more, and what each is measured against. |
| 3 | Where Base Comes From | Attack, spell and minion archetypes. Local against global. Conversion and gain. |
| 4 | From Theme to Skeleton | Which early decisions commit you, which defer, and the order to take them in. |
| 5 | Enemy-Side Scaling | Monster resistance and armour. Penetration, exposure, curses, damage-taken effects. |
| 10 | Slot-to-Bucket Mapping | Which slots can supply which statistic, and noticing when what you need has no home left. |
| 11 | Reading an Item | Judging a drop in seconds. Why the biggest single number usually loses. |
| 12 | Crafting Fundamentals | Currency as operations, attempts rather than outcomes, and when to stop. |
| 13 | A Craft, Start to Finish | The determinism inventory, crafting as a flowchart, and a full worked walkthrough. |
Lessons 6 to 9 — the viability checklist, crit, defence and the audit loop — are not written yet. The full sequence is on the roadmap.
Reference
Compressed, revisitable, built to print. These outlive the lessons.
- Roadmap — every topic, in order, with what is built and what is coming
- Damage Formula — the six layers and the one division, on one page
- Glossary — every term defined once and used consistently
Where to start
In order. Lesson 1 is proportional reasoning applied to real in-game situations, and everything after it assumes that arithmetic is comfortable. It is mostly practice, with problems generated endlessly and nothing scored or stored.
Lessons carry a fixed header with the contents of the page and links forward and back. On a wide screen the contents also sit in the left margin and track the section you are reading.
Claims are cited to the community wiki, Maxroll and Mobalytics. Where those sources disagree — as they do on the armour formula — the disagreement is stated rather than resolved. Path of Exile 2 has no published specification, so parts of its damage pipeline are community reverse-engineering rather than documented fact.