diff --git a/lib/lua/runtime.sx b/lib/lua/runtime.sx
index d8b1fe8c..6fb811da 100644
--- a/lib/lua/runtime.sx
+++ b/lib/lua/runtime.sx
@@ -968,11 +968,16 @@
 (define
   lua-string-match
   (fn (&rest args)
-    (let ((s (first args)) (pat (nth args 1)))
-      (let ((idx (index-of s pat)))
-        (cond
-          ((< idx 0) nil)
-          (else pat))))))
+    (let ((s (first args)) (pat (nth args 1))
+          (init (if (> (len args) 2) (nth args 2) 1)))
+      (let ((start-i0 (cond
+                        ((< init 0) (let ((v (+ (len s) init))) (if (< v 0) 0 v)))
+                        ((= init 0) 0)
+                        (else (- init 1)))))
+        (let ((r (lua-pat-find pat s start-i0)))
+          (cond
+            ((= r nil) nil)
+            (else (substring s (first r) (nth r 1)))))))))
 
 ;; Literal-only string.gmatch: iterator producing each literal match of pat.
 (define
@@ -983,14 +988,14 @@
         (cond
           ((> pos (len s)) nil)
           (else
-            (let ((rest-str (if (= pos 0) s (substring s pos (len s)))))
-              (let ((idx (index-of rest-str pat)))
-                (cond
-                  ((< idx 0) (begin (set! pos (+ (len s) 1)) nil))
-                  (else
+            (let ((r (lua-pat-find pat s pos)))
+              (cond
+                ((= r nil) (begin (set! pos (+ (len s) 1)) nil))
+                (else
+                  (let ((start (first r)) (end (nth r 1)))
                     (begin
-                      (set! pos (+ pos idx (len pat)))
-                      pat)))))))))))
+                      (set! pos (if (= end start) (+ end 1) end))
+                      (substring s start end))))))))))))
 
 ;; Literal-only string.gsub: replace all occurrences of pat with repl (string only for now).
 (define
@@ -1006,28 +1011,42 @@
           (let ((out "") (pos 0) (count 0) (done false))
             (begin
               (define
-                loop
+                gsub-loop
                 (fn ()
                   (when (and (not done) (<= pos (len s)))
-                    (let ((rest-str (if (= pos 0) s (substring s pos (len s)))))
-                      (let ((idx (index-of rest-str pat)))
-                        (cond
-                          ((< idx 0)
-                            (begin
-                              (set! out (str out rest-str))
-                              (set! done true)))
-                          ((and (>= max-n 0) (>= count max-n))
-                            (begin
-                              (set! out (str out rest-str))
-                              (set! done true)))
-                          (else
-                            (let ((before (substring rest-str 0 idx)))
-                              (begin
-                                (set! out (str out before (if (= (type-of repl) "string") repl (str repl))))
-                                (set! pos (+ pos idx (len pat)))
-                                (set! count (+ count 1))
-                                (loop))))))))))
-              (loop)
+                    (let ((r (lua-pat-find pat s pos)))
+                      (cond
+                        ((= r nil)
+                          (begin
+                            (set! out (str out (substring s pos (len s))))
+                            (set! done true)))
+                        ((and (>= max-n 0) (>= count max-n))
+                          (begin
+                            (set! out (str out (substring s pos (len s))))
+                            (set! done true)))
+                        (else
+                          (let ((start (first r)) (end (nth r 1)))
+                            (let ((matched (substring s start end)))
+                              (let ((replacement
+                                      (cond
+                                        ((= (type-of repl) "string") repl)
+                                        ((or (= (type-of repl) "function") (= (type-of repl) "lambda"))
+                                          (let ((rv (lua-call repl matched)))
+                                            (cond
+                                              ((or (= rv nil) (= rv false)) matched)
+                                              (else (str rv)))))
+                                        ((= (type-of repl) "dict")
+                                          (let ((v (get repl matched)))
+                                            (cond
+                                              ((= v nil) matched)
+                                              (else (str v)))))
+                                        (else (str repl)))))
+                                (begin
+                                  (set! out (str out (substring s pos start) replacement))
+                                  (set! pos (if (= end start) (+ end 1) end))
+                                  (set! count (+ count 1))
+                                  (gsub-loop)))))))))))
+              (gsub-loop)
               (list (quote lua-multi) out count))))))))
 
 ;; Basic string.format: %s %d %f (%%.Nf ignored), %%.
diff --git a/lib/lua/scoreboard.json b/lib/lua/scoreboard.json
index 4f48fa7e..0b6bce3d 100644
--- a/lib/lua/scoreboard.json
+++ b/lib/lua/scoreboard.json
@@ -51,7 +51,7 @@
       "name": "attrib.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: module 'C' not found\\\\\\\"\\",
-      "ms": 6112
+      "ms": 6137
     },
     {
       "name": "big.lua",
@@ -63,7 +63,7 @@
       "name": "calls.lua",
       "status": "fail",
       "reason": "undefined symbol: fat\\",
-      "ms": 4800
+      "ms": 4744
     },
     {
       "name": "checktable.lua",
@@ -87,7 +87,7 @@
       "name": "constructs.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to compare incompat",
-      "ms": 6618
+      "ms": 6638
     },
     {
       "name": "db.lua",
@@ -99,13 +99,13 @@
       "name": "errors.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 3080
+      "ms": 3109
     },
     {
       "name": "events.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 7192
+      "ms": 7069
     },
     {
       "name": "files.lua",
@@ -123,13 +123,13 @@
       "name": "literals.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 1777
+      "ms": 1866
     },
     {
       "name": "locals.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
-      "ms": 1644
+      "ms": 1612
     },
     {
       "name": "main.lua",
@@ -141,43 +141,43 @@
       "name": "math.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 3999
+      "ms": 3983
     },
     {
       "name": "nextvar.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 6948
+      "ms": 6968
     },
     {
       "name": "pm.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 6326
+      "ms": 5852
     },
     {
       "name": "sort.lua",
       "status": "timeout",
       "reason": "per-test timeout",
-      "ms": 8008
+      "ms": 8007
     },
     {
       "name": "strings.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 3975
+      "ms": 3925
     },
     {
       "name": "vararg.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 2152
+      "ms": 2195
     },
     {
       "name": "verybig.lua",
       "status": "pass",
       "reason": "",
-      "ms": 562
+      "ms": 930
     }
   ]
 }
\ No newline at end of file
diff --git a/lib/lua/scoreboard.md b/lib/lua/scoreboard.md
index c2093f26..b719d360 100644
--- a/lib/lua/scoreboard.md
+++ b/lib/lua/scoreboard.md
@@ -18,25 +18,25 @@ fail=12 timeout=3 skip=8 total=24
 |---|---|---|---:|
 | all.lua | skip | driver uses dofile to chain other tests | 0 |
 | api.lua | skip | requires testC (C debug library) | 0 |
-| attrib.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: module 'C' not found\\\"\ | 6112 |
+| attrib.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: module 'C' not found\\\"\ | 6137 |
 | big.lua | timeout | per-test timeout | 8008 |
-| calls.lua | fail | undefined symbol: fat\ | 4800 |
+| calls.lua | fail | undefined symbol: fat\ | 4744 |
 | checktable.lua | skip | internal debug helpers | 0 |
 | closure.lua | timeout | per-test timeout | 8008 |
 | code.lua | skip | bytecode inspection via debug library | 0 |
-| constructs.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to compare incompat | 6618 |
+| constructs.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to compare incompat | 6638 |
 | db.lua | skip | debug library | 0 |
-| errors.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3080 |
-| events.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 7192 |
+| errors.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3109 |
+| events.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 7069 |
 | files.lua | skip | io library | 0 |
 | gc.lua | skip | collectgarbage / finalisers | 0 |
-| literals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1777 |
-| locals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 1644 |
+| literals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1866 |
+| locals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 1612 |
 | main.lua | skip | standalone interpreter driver | 0 |
-| math.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3999 |
-| nextvar.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6948 |
-| pm.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6326 |
-| sort.lua | timeout | per-test timeout | 8008 |
-| strings.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3975 |
-| vararg.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 2152 |
-| verybig.lua | pass | - | 562 |
+| math.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3983 |
+| nextvar.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6968 |
+| pm.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 5852 |
+| sort.lua | timeout | per-test timeout | 8007 |
+| strings.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3925 |
+| vararg.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 2195 |
+| verybig.lua | pass | - | 930 |
diff --git a/lib/lua/test.sh b/lib/lua/test.sh
index 8ef4ec8f..22922649 100755
--- a/lib/lua/test.sh
+++ b/lib/lua/test.sh
@@ -964,6 +964,20 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 1881)
 (eval "(lua-eval-ast \"local function f() return 10, 20 end return (f()) + 1\")")
 
+;; ── Lua patterns in match/gmatch/gsub ────────────────────────
+(epoch 1890)
+(eval "(lua-eval-ast \"return string.match(\\\"hello123world\\\", \\\"%d+\\\")\")")
+(epoch 1891)
+(eval "(lua-eval-ast \"return string.match(\\\"name=bob\\\", \\\"%a+\\\")\")")
+(epoch 1892)
+(eval "(lua-eval-ast \"local c = 0 for w in string.gmatch(\\\"a b c d\\\", \\\"%a\\\") do c = c + 1 end return c\")")
+(epoch 1893)
+(eval "(lua-eval-ast \"local r, n = string.gsub(\\\"1 + 2 = 3\\\", \\\"%d\\\", \\\"X\\\") return r .. \\\":\\\" .. n\")")
+(epoch 1894)
+(eval "(lua-eval-ast \"if string.find(\\\"hello\\\", \\\"^hel\\\") then return 1 else return 0 end\")")
+(epoch 1895)
+(eval "(lua-eval-ast \"if string.find(\\\"hello\\\", \\\"^wor\\\") then return 0 else return 1 end\")")
+
 EPOCHS
 
 OUTPUT=$(timeout 60 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
@@ -1460,6 +1474,14 @@ check 1870 "a:add():add():add().x chain"    '60'
 check 1880 "(f()) scalar coerce"            '1'
 check 1881 "(f()) + 1 scalar"               '11'
 
+# ── Lua patterns in match/gmatch/gsub ────────────────────────
+check 1890 "match %d+"                      '"123"'
+check 1891 "match %a+"                      '"name"'
+check 1892 "gmatch %a count"                '4'
+check 1893 "gsub %d → X"                    '"X + X = X:3"'
+check 1894 "find ^ anchor hit"              '1'
+check 1895 "find ^ anchor miss"             '1'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL Lua-on-SX tests passed"
diff --git a/plans/lua-on-sx.md b/plans/lua-on-sx.md
index e09eb546..09af73fa 100644
--- a/plans/lua-on-sx.md
+++ b/plans/lua-on-sx.md
@@ -82,6 +82,7 @@ Each item: implement → tests → tick box → update progress log.
 
 _Newest first. Agent appends on every commit._
 
+- 2026-04-24: lua: scoreboard iteration — extended pattern engine to `string.match`/`gmatch`/`gsub`. `gsub` now supports string/function/table replacement modes. 381/381 green (+6 pattern tests).
 - 2026-04-24: lua: scoreboard iteration — **Lua pattern engine (minimal)** for `string.find`. Supports character classes (`%d`/`%a`/`%s`/`%w`/`%p`/`%l`/`%u`/`%c`/`%x` + complements), `.` any, `^`/`$` anchors, quantifiers `*`/`+`/`-`/`?`, literal chars, `%%`. Added `plain` arg pathway. match/gmatch/gsub still literal. Scoreboard unchanged (pattern-using tests still hit other issues downstream).
 - 2026-04-24: lua: scoreboard iteration — `package.cpath`/`config`/`loaders`/`searchers`/`searchpath` stubs. attrib.lua moves from #9 (checking `package.cpath` is a string) to "module 'C' not found" — test requires filesystem-based module loading, not tractable. Most remaining failures need Lua pattern matching (pm.lua/strings.lua), env tracking (locals.lua/events.lua), or filesystem (attrib.lua).
 - 2026-04-24: lua: scoreboard iteration — **parenthesized expressions truncate multi-return** (Lua spec: `(f())` forces single value even if `f` returns multi). Parser wraps `(expr)` in a new `lua-paren` AST node; transpile emits `(lua-first inner)`. Fixes `constructs.lua`@30 (`a,b,c = (f())` expects `a=1, b=nil, c=nil`) and `math.lua`@13. 375/375 green (+2 paren tests). Scoreboard: 8× asserts (was 10).