diff --git a/lib/lua/runtime.sx b/lib/lua/runtime.sx
index 3f4fa4be..1880f2ed 100644
--- a/lib/lua/runtime.sx
+++ b/lib/lua/runtime.sx
@@ -990,10 +990,28 @@
   lua-string-byte
   (fn (&rest args)
     (let ((s (first args))
-          (i (if (> (len args) 1) (nth args 1) 1)))
-      (cond
-        ((or (< i 1) (> i (len s))) nil)
-        (else (char-code (char-at s (- i 1))))))))
+          (i-raw (if (> (len args) 1) (nth args 1) nil))
+          (j-raw (if (> (len args) 2) (nth args 2) nil)))
+      (let ((i (if (= i-raw nil) 1 i-raw)))
+        (let ((j (if (= j-raw nil) i j-raw)))
+          (let ((slen (len s)))
+            (let ((ni (cond ((< i 0) (+ slen i 1)) ((= i 0) 1) (else i)))
+                  (nj (cond ((< j 0) (+ slen j 1)) (else j))))
+              (cond
+                ((or (< ni 1) (> ni slen) (< nj ni)) nil)
+                ((= ni nj) (char-code (char-at s (- ni 1))))
+                (else
+                  (let ((out (list (quote lua-multi))))
+                    (begin
+                      (define
+                        b-loop
+                        (fn (k)
+                          (when (and (<= k nj) (<= k slen))
+                            (begin
+                              (set! out (append out (list (char-code (char-at s (- k 1))))))
+                              (b-loop (+ k 1))))))
+                      (b-loop ni)
+                      out)))))))))))
 
 (define
   lua-char-one
diff --git a/lib/lua/scoreboard.json b/lib/lua/scoreboard.json
index 0946325e..0c1f859b 100644
--- a/lib/lua/scoreboard.json
+++ b/lib/lua/scoreboard.json
@@ -51,19 +51,19 @@
       "name": "attrib.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: module 'C' not found\\\\\\\"\\",
-      "ms": 6636
+      "ms": 6698
     },
     {
       "name": "big.lua",
       "status": "timeout",
       "reason": "per-test timeout",
-      "ms": 8008
+      "ms": 8002
     },
     {
       "name": "calls.lua",
       "status": "fail",
       "reason": "undefined symbol: fat\\",
-      "ms": 5129
+      "ms": 5168
     },
     {
       "name": "checktable.lua",
@@ -87,7 +87,7 @@
       "name": "constructs.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to compare incompat",
-      "ms": 6962
+      "ms": 7174
     },
     {
       "name": "db.lua",
@@ -99,13 +99,13 @@
       "name": "errors.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 3442
+      "ms": 3446
     },
     {
       "name": "events.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 7474
+      "ms": 7749
     },
     {
       "name": "files.lua",
@@ -123,13 +123,13 @@
       "name": "literals.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 1965
+      "ms": 1931
     },
     {
       "name": "locals.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
-      "ms": 1784
+      "ms": 1767
     },
     {
       "name": "main.lua",
@@ -141,43 +141,43 @@
       "name": "math.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
-      "ms": 4413
+      "ms": 4412
     },
     {
       "name": "nextvar.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 7389
+      "ms": 7512
     },
     {
       "name": "pm.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 6252
+      "ms": 6522
     },
     {
       "name": "sort.lua",
       "status": "timeout",
       "reason": "per-test timeout",
-      "ms": 8004
+      "ms": 8008
     },
     {
       "name": "strings.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 4236
+      "ms": 4282
     },
     {
       "name": "vararg.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 2348
+      "ms": 2373
     },
     {
       "name": "verybig.lua",
       "status": "pass",
       "reason": "",
-      "ms": 1074
+      "ms": 1080
     }
   ]
 }
\ No newline at end of file
diff --git a/lib/lua/scoreboard.md b/lib/lua/scoreboard.md
index 2fc7cca1..b2b79717 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\\\"\ | 6636 |
-| big.lua | timeout | per-test timeout | 8008 |
-| calls.lua | fail | undefined symbol: fat\ | 5129 |
+| attrib.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: module 'C' not found\\\"\ | 6698 |
+| big.lua | timeout | per-test timeout | 8002 |
+| calls.lua | fail | undefined symbol: fat\ | 5168 |
 | checktable.lua | skip | internal debug helpers | 0 |
 | closure.lua | timeout | per-test timeout | 8001 |
 | code.lua | skip | bytecode inspection via debug library | 0 |
-| constructs.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to compare incompat | 6962 |
+| constructs.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to compare incompat | 7174 |
 | db.lua | skip | debug library | 0 |
-| errors.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3442 |
-| events.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 7474 |
+| errors.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3446 |
+| events.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 7749 |
 | files.lua | skip | io library | 0 |
 | gc.lua | skip | collectgarbage / finalisers | 0 |
-| literals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1965 |
-| locals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 1784 |
+| literals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1931 |
+| locals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 1767 |
 | main.lua | skip | standalone interpreter driver | 0 |
-| math.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 4413 |
-| nextvar.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 7389 |
-| pm.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6252 |
-| sort.lua | timeout | per-test timeout | 8004 |
-| strings.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4236 |
-| vararg.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 2348 |
-| verybig.lua | pass | - | 1074 |
+| math.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 4412 |
+| nextvar.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 7512 |
+| pm.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6522 |
+| sort.lua | timeout | per-test timeout | 8008 |
+| strings.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4282 |
+| vararg.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 2373 |
+| verybig.lua | pass | - | 1080 |
diff --git a/plans/lua-on-sx.md b/plans/lua-on-sx.md
index 42fbad15..2f397799 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._
 
+- 2026-04-25: lua: scoreboard iteration — `string.byte(s, i, j)` now returns multi-values for ranges (was single byte only). 393/393 green; scoreboard unchanged.
 - 2026-04-25: lua: scoreboard iteration — `math.sinh`/`cosh`/`tanh` (Lua 5.1 hyperbolic). 393/393 green; scoreboard unchanged.
 - 2026-04-25: lua: scoreboard iteration — tried two-phase eval (extract top-level `function f` decls, evaluate them BEFORE the guard so they leak to top-level env, then run the rest inside guard). Broke method-decl tests because `function a:add(...)` requires `a` to exist, and `a = {...}` was in the deferred phase-2. Reverted. Real fix needs `_G` table or AST-level rewriting of top-level returns into chunk-result mutations. 393/393 green.
 - 2026-04-25: lua: scoreboard iteration — `string.dump` stub (returns string-of-fn). Diagnosed calls.lua: file ENDS with `return deep` (line 295), which makes my `lua-has-top-return?` correctly return true, triggering the guard, which scopes user defines and breaks loadstring's lexical capture of `fat`. The fix would require either rewriting top-level returns into a different mechanism (post-processing the AST) or implementing a real `_G` global table for global assignment/lookup. Both larger.