diff --git a/packages/maps/dev_aqueous.cgz b/packages/maps/dev_aqueous.cgz
index 690d7cc9..2c39ff6f 100644
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diff --git a/packages/maps/dev_arabian.cgz b/packages/maps/dev_arabian.cgz
index 03dbdbf2..1d95d171 100644
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diff --git a/packages/maps/dev_arctic.cgz b/packages/maps/dev_arctic.cgz
index 5efc64da..c20bf353 100644
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diff --git a/packages/maps/dev_arid.cgz b/packages/maps/dev_arid.cgz
index 609ee3f9..8a47647d 100644
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diff --git a/packages/maps/dev_avenue.cgz b/packages/maps/dev_avenue.cgz
index 4fe3972c..8311d47a 100644
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diff --git a/packages/maps/dev_cavern.cgz b/packages/maps/dev_cavern.cgz
index 127416fa..41289df8 100644
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diff --git a/packages/maps/dev_complex.cgz b/packages/maps/dev_complex.cgz
index 546dc33b..14111de4 100644
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diff --git a/packages/maps/dev_depot.cgz b/packages/maps/dev_depot.cgz
index d60024bd..5ceae869 100644
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diff --git a/packages/maps/dev_desert.cgz b/packages/maps/dev_desert.cgz
index 1e359151..5b1a75af 100644
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diff --git a/packages/maps/dev_desert2.cgz b/packages/maps/dev_desert2.cgz
index 26b269a5..aac26f23 100644
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diff --git a/packages/maps/dev_desert3.cgz b/packages/maps/dev_desert3.cgz
index 4f14c14f..59ed64fb 100644
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diff --git a/packages/maps/dev_douze.cgz b/packages/maps/dev_douze.cgz
index 6286781a..ba82b047 100644
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diff --git a/packages/maps/dev_edifice.cgz b/packages/maps/dev_edifice.cgz
index 148dde72..80c7c2a8 100644
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diff --git a/packages/maps/dev_elevation.cgz b/packages/maps/dev_elevation.cgz
index b4a30024..3065ce96 100644
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diff --git a/packages/maps/dev_gothic.cgz b/packages/maps/dev_gothic.cgz
index 1030d109..fec1658a 100644
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diff --git a/packages/maps/dev_iceroad.cgz b/packages/maps/dev_iceroad.cgz
index 47aca4a2..972b5b19 100644
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diff --git a/packages/maps/dev_industrial.cgz b/packages/maps/dev_industrial.cgz
index c495bade..4587858c 100644
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diff --git a/packages/maps/dev_ingress.cgz b/packages/maps/dev_ingress.cgz
index e597ae6c..b8c6d531 100644
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diff --git a/packages/maps/dev_keller.cgz b/packages/maps/dev_keller.cgz
index 28c9d4c7..e1a5019e 100644
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diff --git a/packages/maps/dev_lainio.cgz b/packages/maps/dev_lainio.cgz
index 1b03665e..903c7a9d 100644
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diff --git a/packages/maps/dev_mines.cgz b/packages/maps/dev_mines.cgz
index 33ef9fb1..be8470d1 100644
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diff --git a/packages/maps/dev_outpost.cgz b/packages/maps/dev_outpost.cgz
index 7ca7db3f..047500f8 100644
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diff --git a/packages/maps/dev_power.cgz b/packages/maps/dev_power.cgz
index 69e3d8ed..af750762 100644
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diff --git a/packages/maps/dev_rattrap.cgz b/packages/maps/dev_rattrap.cgz
index e5b1da86..2f7ff692 100644
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diff --git a/packages/maps/dev_scaffold.cgz b/packages/maps/dev_scaffold.cgz
index b60de7a2..59528da4 100644
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diff --git a/packages/maps/dev_shine.cgz b/packages/maps/dev_shine.cgz
index 44c246a3..9e8a3344 100644
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diff --git a/packages/maps/dev_snow.cgz b/packages/maps/dev_snow.cgz
index 4a51f63c..e6776733 100644
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diff --git a/packages/maps/dev_stellar.cgz b/packages/maps/dev_stellar.cgz
index dc435ef5..55fc69e5 100644
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diff --git a/packages/maps/dev_sunset.cgz b/packages/maps/dev_sunset.cgz
index af1342dc..2478b44e 100644
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diff --git a/packages/maps/dev_swamp.cgz b/packages/maps/dev_swamp.cgz
index 383cd664..3fa28c4e 100644
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diff --git a/packages/maps/dev_terros.cgz b/packages/maps/dev_terros.cgz
index 8c08f607..a942fbba 100644
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diff --git a/packages/maps/dev_toxic.cgz b/packages/maps/dev_toxic.cgz
index c7337ad9..02d245cc 100644
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diff --git a/packages/maps/dev_urban.cgz b/packages/maps/dev_urban.cgz
index 0ea43cd7..e6f50435 100644
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diff --git a/packages/maps/dev_venison.cgz b/packages/maps/dev_venison.cgz
index ec531d2b..27474226 100644
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diff --git a/packages/maps/dev_wasteland.cgz b/packages/maps/dev_wasteland.cgz
index e0238cc2..5bbff724 100644
Binary files a/packages/maps/dev_wasteland.cgz and b/packages/maps/dev_wasteland.cgz differ
diff --git a/packages/maps/dev_werk.cgz b/packages/maps/dev_werk.cgz
index 91247e11..fbc4340f 100644
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diff --git a/source/dev_tools/create_map_license_summary.cfg b/source/dev_tools/create_map_license_summary.cfg
new file mode 100644
index 00000000..4675cce4
--- /dev/null
+++ b/source/dev_tools/create_map_license_summary.cfg
@@ -0,0 +1,34 @@
+// - batch-update map license information
+// - generate maps_readme.txt (map license summary file)
+// (requires debug binary of game client, because of loadmap and debugline)
+
+tempalias maplist [dev_aqueous dev_arabian dev_arctic dev_arid dev_avenue dev_cavern dev_complex dev_depot dev_desert dev_desert2 dev_desert3 dev_douze dev_edifice dev_elevation
+ dev_gothic dev_iceroad dev_industrial dev_ingress dev_keller dev_lainio dev_mines dev_outpost dev_power dev_rattrap dev_scaffold dev_shine dev_snow dev_stellar dev_sunset
+ dev_swamp dev_terros dev_toxic dev_urban dev_venison dev_wasteland dev_werk]
+
+tempalias lfn maps_license.txt
+debugline $lfn "TO ENSURE YOU HAVE NO ERRORS WITH ASSAULTCUBE:\n\t* Don't edit, rename or delete ANY files in this directory.\n\t* Don't add files to this directory.\n"
+debugline $lfn "This folder contains all builtin (a.k.a. \"official\") maps.\nEach map contains embedded information about author and license, accessible from within the game.\nHere's a summary:\n"
+
+if 0 [ looplist [
+new_content cc-by-nc-sa-3.0 "by foo, email: foo@bar.org"
+] [ m l cc ] [
+  loadmap $m
+  if (strlen $l) [ mapinfo_license $l ]
+  if (strlen $cc) [ mapinfo_comment $cc ]
+  if (+ (strlen $l) (strlen $cc)) [ savemap $m ]
+] ]
+
+looplist $maplist m [
+  loadmap $m
+  debugline $lfn (concatword $mapmsg "    (" $m ".cgz, size " (mapsize) ", revision " $curmaprevision ")")
+  if (< (findlist $__maplicense_list $mapinfo_license) 0) [
+    debugline $lfn (concatword "map license tag: \"" $mapinfo_license "\"")
+  ] [
+    debugline $lfn  (getalias (concatword __maplicense_fullname_ $mapinfo_license))
+  ]
+  if (strlen $mapinfo_comment) [
+  debugline $lfn $mapinfo_comment
+  ]
+  debugline $lfn ""
+]
diff --git a/source/src/command.cpp b/source/src/command.cpp
index e2cdca66..df47376e 100644
--- a/source/src/command.cpp
+++ b/source/src/command.cpp
@@ -1875,3 +1875,18 @@ void debugargs(char **args, int numargs)
 }
 
 COMMAND(debugargs, "v");
+
+#ifndef STANDALONE
+#ifdef _DEBUG
+void debugline(char *fname, char *line) // print one line to a logfile
+{
+    if(!multiplayer())
+    {
+        stream *f = openfile(behindpath(fname), "a");
+        if(f) f->printf("%s\n", line);
+        if(f) delete f;
+    }
+}
+COMMAND(debugline, "ss");
+#endif
+#endif
diff --git a/source/src/worldio.cpp b/source/src/worldio.cpp
index 7825154d..ca9e85f8 100644
--- a/source/src/worldio.cpp
+++ b/source/src/worldio.cpp
@@ -938,6 +938,13 @@ bool load_world(char *mname)        // still supports all map formats that have
     return true;
 }
 
+#ifdef _DEBUG
+COMMANDF(loadmap, "s", (char *mapname)
+{
+    if(!multiplayer()) load_world(mapname);
+});
+#endif
+
 // support reading and writing binary data in config files
 
 static bool hexbinenabled = false;