The Guitarist's Theory Roadmap: Order Beats Effort

The short answer: most self-taught theory journeys fail from bad sequencing, not bad effort — modes before intervals, the circle of fifths before knowing the notes. Here's the dependency-ordered path: (1) fretboard notes → (2) intervals & degrees → (3) triads and chords-from-scales → (4) keys, numerals & the circle → (5) seventh chords, borrowed chords, modes. Each stage makes the next one easy; skipping ahead makes everything hard.

(Still deciding whether to walk this road at all? Do you even need theory? — short version: no, but it's cheap and it compounds.)

Stage 1: The note map (weeks 1–6, alongside everything else)

Memorize the fretboard — anchor strings, octave shapes, daily randomized drills. This isn't really "theory," which is exactly why it's stage 1: every later concept assumes you can find an F♯ without archaeology. Ten minutes a day; it runs in the background of all other stages.

You're done when: any string, any fret, under two seconds.

Stage 2: Intervals and degrees (weeks 3–8, overlapping)

The two naming systems everything else is written in: intervals (distances — learn thirds and fifths as shapes first) and scale degrees (positions relative to home). The major scale enters here as the ruler — one position by degree numbers, one string by formula.

You're done when: you can find the 3, 5, and ♭7 from any root without counting, and W-W-H-W-W-W-H means something physical.

Stage 3: Chords stop being grips (weeks 6–12)

The stage where the guitar starts explaining itself: triads (the 1-3-5 machine), the one-fret major/minor switch, why every key owns seven chords, and barre chords revealing themselves as movable systems. Do the triad drills — this stage must reach the hands, not just the head.

You're done when: given any key, you can name and play its I, IV, V, and vi without pausing.

Stage 4: The key level (weeks 10–16)

Zoom out from chords to the systems containing them: finding the key of any song, Roman numerals and number-thinking, key signatures, and the circle of fifths — which at this stage assembles itself from parts you already own. Number-ize your repertoire; transpose things for fun.

You're done when: "it's a 1-5-6-4 in E" is a complete, playable sentence.

Stage 5: The spice rack (months 4+, forever, happily)

Only now — with notes, intervals, chords, and keys solid — do the fancy topics land as easy: seventh chords (one more stack), borrowed chords and secondary dominants (four nicknamed cheats), modes (degrees with different homes — trivially, at this point), the three minors, ear training as a lifestyle. Notice that every one of these was impossibly confusing in week 1 and is a shrug in month 4. That's sequencing.

The three rules that make it stick

Everything on the neck within five minutes. Theory that stays on paper evaporates. Every concept above has a fretboard drill — do that part.
Ten minutes daily beats Sunday marathons — the spaced-repetition math doesn't care about your enthusiasm, only your consistency. If you want the daily session pre-structured, here's the 10-minute template.
Stay musical. Every stage should touch real songs the same week. Theory explains music; without the music there's nothing to explain.