diff --git a/README.md b/README.md
index 03e7f18..2a37d12 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@ In the creator, the Concept page only has a "Rules preset" selector. Presets are
 
 ### Skills, proficiency and expertise
 
-- `creation.advanced_unlock_cost`: pool points needed to unlock an advanced skill (free if a profession or proficiency covers it).
+- `creation.advanced_unlock_cost`: pool points needed to unlock an advanced skill (free if the character's profession grants proficiency in it; proficiency picks do not unlock a skill).
 - `creation.free_proficiencies`: free proficiency picks every character gets. Talents can add more with `"proficiency_picks": N` (see "Versatile Training").
 - Proficiency is +`proficiency_bonus`; two picks on one skill (a profession proficiency counts as one) give Expertise, +`expertise_bonus`.
 
diff --git a/backend/app/derive.py b/backend/app/derive.py
index 9faa5b4..bc347cf 100644
--- a/backend/app/derive.py
+++ b/backend/app/derive.py
@@ -37,7 +37,7 @@ def compute(ch: dict, rules: dict) -> dict:
         pips = prof_pip + max(0, free_pips)
         prof = [0, cr["proficiency_bonus"], cr["expertise_bonus"]][pips]
         unlocked = s["id"] in (ch.get("unlocked") or [])
-        usable = s["type"] == "basic" or unlocked or prof > 0  # advanced skills must be unlocked
+        usable = s["type"] == "basic" or unlocked or prof_pip > 0  # advanced skills must be unlocked (a profession proficiency does it for free)
         best = max(attrs[a] for a in s["attrs"])  # with several attributes the higher one counts
         skills.append({**s, "points": pts, "prof": prof, "pips": pips, "usable": usable, "unlocked": unlocked,
                        "total": best + pts + prof})
diff --git a/backend/data/rules.json b/backend/data/rules.json
index 7530cf1..b8a06e5 100644
--- a/backend/data/rules.json
+++ b/backend/data/rules.json
@@ -421,7 +421,7 @@
             "Proficiency: +10. Expertise: +20.",
             "Every character gets 2 free proficiency picks on top of the profession's proficiencies. A talent can grant 2 more.",
             "Putting two proficiency picks into the same skill makes it Expertise (a profession proficiency counts as one of the two).",
-            "Proficiency in an advanced skill unlocks it for free.",
+            "Proficiency picks can only be used on skills you can use, so an advanced skill has to be unlocked first.",
             "Groups: Combat, Survival, Social, Technical, Knowledge & Mental."
           ]
         },
diff --git a/frontend/src/Creator.jsx b/frontend/src/Creator.jsx
index 20ba1b9..2bac4bc 100644
--- a/frontend/src/Creator.jsx
+++ b/frontend/src/Creator.jsx
@@ -134,6 +134,7 @@ export default function Creator({ rules: baseRules, user, loadRequest, clearLoad
 
   // Click on pip k (1 = Proficient, 2 = Expertise) of a skill: sets the skill's total pips to k, or one lower if already there.
   const clickPip = (s, k) => {
+    if (!s.usable) return flash('Unlock this advanced skill first.')
     const target = s.pips >= k ? k - 1 : k
     const wantFree = Math.max(0, target - s.profPip)
     if (wantFree - s.freePips > c.profLeft) return flash('No proficiency picks left.')
@@ -263,7 +264,7 @@ export default function Creator({ rules: baseRules, user, loadRequest, clearLoad
       <h2>Skills</h2>
       <p className="muted">
         At most half the attribute per skill. Advanced skills must be unlocked first for {c.unlockCost} points from the pool
-        (free if your profession grants them). The pool size comes from the rules preset.
+        (free if your profession grants proficiency in them). The pool size comes from the rules preset.
       </p>
       <div className="pools">
         <div className={`pool ${c.skillLeft < 0 ? 'over' : ''}`}>
@@ -275,7 +276,7 @@ export default function Creator({ rules: baseRules, user, loadRequest, clearLoad
       </div>
       <p className="small muted">
         Proficiency adds +{cr.proficiency_bonus}. Two picks on the same skill make it Expertise (+{cr.expertise_bonus}); a profession proficiency counts as one of them.
-        Proficiency in an advanced skill unlocks it for free. The talent "Versatile Training" grants 2 more picks.
+        Proficiency picks only work on skills you can use, so unlock an advanced skill first. The talent "Versatile Training" grants 2 more picks.
       </p>
       {rules.skill_groups.map((g) => (
         <div key={g.id}>
@@ -295,8 +296,8 @@ export default function Creator({ rules: baseRules, user, loadRequest, clearLoad
                       <span className="small muted">Training</span>
                       {[1, 2].map((k) => (
                         <button key={k} className={`pip ${s.pips >= k ? 'on' : ''} ${s.profPip >= k ? 'from-prof' : ''}`}
-                          disabled={s.profPip >= k} onClick={() => clickPip(s, k)}
-                          title={s.profPip >= k ? 'From your profession' : k === 2 ? 'Expertise (uses 2 picks in total)' : 'Proficiency'}
+                          disabled={s.profPip >= k || !s.usable} onClick={() => clickPip(s, k)}
+                          title={!s.usable ? 'Unlock the skill first' : s.profPip >= k ? 'From your profession' : k === 2 ? 'Expertise (uses 2 picks in total)' : 'Proficiency'}
                           aria-label={`${s.name} proficiency ${k}`}>{s.pips >= k ? '◆' : '◇'}</button>
                       ))}
                     </div>
@@ -309,8 +310,8 @@ export default function Creator({ rules: baseRules, user, loadRequest, clearLoad
                   ) : (
                     <div className="stepper">
                       {s.type === 'advanced' && !s.free && (
-                        <button className="ghost small-btn" title={`Lock again and get ${c.unlockCost} points back`}
-                          onClick={() => setCh((x) => ({ ...x, unlocked: x.unlocked.filter((id) => id !== s.id), skill_points: { ...x.skill_points, [s.id]: 0 } }))}>Lock</button>
+                        <button className="ghost small-btn" title={`Lock again: you get ${c.unlockCost} points back, its points and proficiency picks are returned`}
+                          onClick={() => setCh((x) => ({ ...x, unlocked: x.unlocked.filter((id) => id !== s.id), skill_points: { ...x.skill_points, [s.id]: 0 }, proficiency_picks: { ...x.proficiency_picks, [s.id]: 0 } }))}>Lock</button>
                       )}
                       <button onClick={() => setPts(s.points - 1)} aria-label={`${s.name} minus`}>−</button>
                       <span className="val">{s.points}</span>
diff --git a/frontend/src/calc.js b/frontend/src/calc.js
index 7ea9377..88e8cd8 100644
--- a/frontend/src/calc.js
+++ b/frontend/src/calc.js
@@ -82,19 +82,20 @@ export function normalize(ch, rules) {
   }
   // The preset may have been deleted since: fall back to whatever matches the numbers
   if (out.preset !== 'custom' && !(rules.presets || []).some((x) => x.id === out.preset)) out.preset = matchPreset(rules, out.creation)
-  // Older characters: advanced skills that already hold points count as unlocked
+  // Older characters: advanced skills that already hold points or proficiency picks count as unlocked
   const unlocked = new Set(out.unlocked)
-  rules.skills.forEach((s) => { if (s.type === 'advanced' && (out.skill_points[s.id] || 0) > 0) unlocked.add(s.id) })
+  rules.skills.forEach((s) => { if (s.type === 'advanced' && ((out.skill_points[s.id] || 0) > 0 || (out.proficiency_picks[s.id] || 0) > 0)) unlocked.add(s.id) })
   return { ...out, unlocked: [...unlocked] }
 }
 
-// Clears points on advanced skills that are neither unlocked nor granted by a profession proficiency.
+// Clears points and proficiency picks on advanced skills that are neither unlocked nor granted by the profession.
 export function pruneLocked(ch, rules) {
   const points = { ...ch.skill_points }
+  const picks = { ...ch.proficiency_picks }
   rules.skills.forEach((s) => {
-    if (s.type === 'advanced' && !ch.unlocked.includes(s.id) && !ch.proficiencies[s.id] && !(ch.proficiency_picks[s.id] > 0)) delete points[s.id]
+    if (s.type === 'advanced' && !ch.unlocked.includes(s.id) && !ch.proficiencies[s.id]) { delete points[s.id]; delete picks[s.id] }
   })
-  return { ...ch, skill_points: points }
+  return { ...ch, skill_points: points, proficiency_picks: picks }
 }
 
 export function kitItems(ch, rules) {
@@ -125,15 +126,15 @@ export function compute(ch, rules) {
     const best = Math.max(...s.attrs.map((a) => attrs[a])) // with several attributes the higher one counts
     const unlocked = ch.unlocked.includes(s.id)
     return { ...s, points, prof, profPip, freePips, pips, unlocked, total: best + points + prof,
-      usable: s.type === 'basic' || unlocked || prof > 0, // advanced skills must be unlocked
-      free: s.type === 'advanced' && prof > 0, // unlocked by the profession, costs nothing
+      usable: s.type === 'basic' || unlocked || profPip > 0, // advanced skills must be unlocked (a profession proficiency does it for free)
+      free: s.type === 'advanced' && profPip > 0, // unlocked by the profession, costs nothing
       max: Math.floor(best / cr.skill_max_divisor) }
   })
 
   const profSpent = skills.reduce((s, x) => s + x.freePips, 0)
   const profAllowed = (cr.free_proficiencies ?? 0) + rules.talents.filter((t) => ch.talents.includes(t.id)).reduce((s, t) => s + (t.proficiency_picks || 0), 0)
   const unlockCost = cr.advanced_unlock_cost ?? 0
-  const paidUnlocks = skills.filter((s) => s.type === 'advanced' && s.unlocked && !s.prof).length
+  const paidUnlocks = skills.filter((s) => s.type === 'advanced' && s.unlocked && !s.profPip).length
   const attrSpent = rules.attributes.reduce((s, a) => s + (ch.attributes[a.id] - cr.attr_start), 0)
   const skillSpent = Object.values(ch.skill_points).reduce((s, v) => s + v, 0) + paidUnlocks * unlockCost
   const chosen = rules.augments.filter((a) => ch.augments.includes(a.id))
diff --git a/frontend/src/explain.js b/frontend/src/explain.js
index 65ae9a5..ed88497 100644
--- a/frontend/src/explain.js
+++ b/frontend/src/explain.js
@@ -33,9 +33,9 @@ export function explainSkill(s, { ch, rules, c }) {
     `Most points you can put in: best attribute ÷ ${cr.skill_max_divisor}, rounded down = ${s.max}`,
   ]
   if (s.type === 'advanced') {
-    lines.push(s.free ? 'Advanced skill: unlocked for free by a proficiency.'
+    lines.push(s.free ? 'Advanced skill: unlocked for free by your profession.'
       : s.unlocked ? `Advanced skill: unlocked (cost ${c.unlockCost} points from the pool).`
-        : `Advanced skill: locked. Unlock it for ${c.unlockCost} points, or get a proficiency in it.`)
+        : `Advanced skill: locked. Unlock it for ${c.unlockCost} points from the pool before you can use it.`)
   }
   if (s.pips === 1 && s.profPip) lines.push('Proficient through your profession.')
   return lines