diff -ur -Xorig1/diff_ignore orig1/common/game.c patch1/common/game.c
--- orig1/common/game.c	Tue Feb 20 08:02:17 2001
+++ patch1/common/game.c	Tue Mar  6 14:27:08 2001
@@ -715,6 +715,7 @@
   game.fogofwar    = GAME_DEFAULT_FOGOFWAR;
   game.fogofwar_old= game.fogofwar;
   game.auto_ai_toggle = GAME_DEFAULT_AUTO_AI_TOGGLE;
+  game.corruptionsize = GAME_DEFAULT_CORRUPTIONSIZE;
   game.barbarianrate  = GAME_DEFAULT_BARBARIANRATE;
   game.onsetbarbarian = GAME_DEFAULT_ONSETBARBARIAN;
   game.nbarbarians = 0;
diff -ur -Xorig1/diff_ignore orig1/common/game.h patch1/common/game.h
--- orig1/common/game.h	Tue Feb 20 08:02:17 2001
+++ patch1/common/game.h	Tue Mar  6 14:16:11 2001
@@ -71,6 +71,7 @@
   int diplchance;
   int cityfactor;
   int civilwarsize;
+  int corruptionsize;
   int min_players, max_players, nplayers;
   int aifill;
   int barbarianrate;
@@ -355,6 +356,10 @@
 #define GAME_DEFAULT_PINGTIMEOUT     60
 #define GAME_MIN_PINGTIMEOUT         60
 #define GAME_MAX_PINGTIMEOUT         1800
+
+#define GAME_DEFAULT_CORRUPTIONSIZE  1
+#define GAME_MIN_CORRUPTIONSIZE      1
+#define GAME_MAX_CORRUPTIONSIZE      150
 
 #define GAME_DEFAULT_BARBARIANRATE   2
 #define GAME_MIN_BARBARIANRATE       0
diff -ur -Xorig1/diff_ignore orig1/server/citytools.c patch1/server/citytools.c
--- orig1/server/citytools.c	Sun Mar  4 23:44:07 2001
+++ patch1/server/citytools.c	Wed Mar  7 18:14:52 2001
@@ -559,6 +559,9 @@
     val /= 2;
   val *= g->corruption_level;
   val /= 100;
+
+  /* corruption penalty if city is smaller than corruptionsize */
+  val = MAX(val, trade * (game.corruptionsize - pcity->size) * 3 / 2 / game.corruptionsize);
   if (val > trade)
     val = trade;
   return(val); /* how did y'all let me forget this one? -- Syela */
diff -ur -Xorig1/diff_ignore orig1/server/savegame.c patch1/server/savegame.c
--- orig1/server/savegame.c	Wed Feb 21 10:13:59 2001
+++ patch1/server/savegame.c	Tue Mar  6 18:40:53 2001
@@ -1673,6 +1673,7 @@
     game.warminglevel  = secfile_lookup_int(file, "game.warminglevel");
     game.nuclearwinter = secfile_lookup_int_default(file, 0, "game.nuclearwinter");
     game.coolinglevel  = secfile_lookup_int_default(file, 8, "game.coolinglevel");
+    game.corruptionsize= secfile_lookup_int_default(file, 1, "game.corruptionsize");
     game.unhappysize   = secfile_lookup_int(file, "game.unhappysize");
 
     if (game.version >= 10100) {
@@ -2004,6 +2005,7 @@
   secfile_insert_int(file, game.warminglevel, "game.warminglevel");
   secfile_insert_int(file, game.nuclearwinter, "game.nuclearwinter");
   secfile_insert_int(file, game.coolinglevel, "game.coolinglevel");
+  secfile_insert_int(file, game.corruptionsize, "game.corruptionsize");
   secfile_insert_int(file, game.unhappysize, "game.unhappysize");
   secfile_insert_int(file, game.cityfactor, "game.cityfactor");
   secfile_insert_int(file, game.civilwarsize, "game.civilwarsize");
diff -ur -Xorig1/diff_ignore orig1/server/stdinhand.c patch1/server/stdinhand.c
--- orig1/server/stdinhand.c	Tue Feb 27 23:50:04 2001
+++ patch1/server/stdinhand.c	Wed Mar  7 17:53:30 2001
@@ -449,7 +449,16 @@
     N_("If a city would expand, but it can't because it needs an Aqueduct "
        "(or Sewer System), it loses this percentage of its foodbox "
        "(or half that amount if it has a Granary).") },
-  
+
+  { "corruptsize", &game.corruptionsize, NULL, NULL,
+    SSET_RULES, SSET_TO_CLIENT,
+    GAME_MIN_CORRUPTIONSIZE, GAME_MAX_CORRUPTIONSIZE, GAME_DEFAULT_CORRUPTIONSIZE,
+    N_("Minimum city size without fixed corruption"),
+    N_("There is a minimum corruption in all cities smaller than this.  "
+       "The minimum is 100% for sizes up to corruptsize/3, and decreases "
+       "gradually to 0% for size=corruptsize.  This does not apply under "
+       "Democracy.") },
+
   { "unhappysize", &game.unhappysize, NULL, NULL,
     SSET_RULES, SSET_TO_CLIENT,
     GAME_MIN_UNHAPPYSIZE, GAME_MAX_UNHAPPYSIZE, GAME_DEFAULT_UNHAPPYSIZE,