diff --git a/src/command.c b/src/command.c
index 651540b5f..24d58a28c 100644
--- a/src/command.c
+++ b/src/command.c
@@ -2241,6 +2241,11 @@ void CV_AddValue(consvar_t *var, INT32 increment)
 					if (var->PossibleValue == kartspeed_cons_t)
 						max++; // Accommodate KARTSPEED_AUTO
 				}
+				else if (var->PossibleValue == gpdifficulty_cons_t
+					&& !M_SecretUnlocked(SECRET_MASTERMODE, false))
+				{
+					max = KARTSPEED_HARD+1;
+				}
 			}
 #ifdef PARANOIA
 			if (currentindice == -1)
diff --git a/src/deh_soc.c b/src/deh_soc.c
index 5da9a4173..1cf6f5d57 100644
--- a/src/deh_soc.c
+++ b/src/deh_soc.c
@@ -2280,10 +2280,10 @@ void readunlockable(MYFILE *f, INT32 num)
 						unlockables[num].type = SECRET_FOLLOWER;
 					else if (fastcmp(word2, "HARDSPEED"))
 						unlockables[num].type = SECRET_HARDSPEED;
+					else if (fastcmp(word2, "MASTERMODE"))
+						unlockables[num].type = SECRET_MASTERMODE;
 					else if (fastcmp(word2, "ENCORE"))
 						unlockables[num].type = SECRET_ENCORE;
-					else if (fastcmp(word2, "LEGACYBOXRUMMAGE"))
-						unlockables[num].type = SECRET_LEGACYBOXRUMMAGE;
 					else if (fastcmp(word2, "TIMEATTACK"))
 						unlockables[num].type = SECRET_TIMEATTACK;
 					else if (fastcmp(word2, "BREAKTHECAPSULES"))
diff --git a/src/k_menudraw.c b/src/k_menudraw.c
index 735f82134..5ad49a066 100644
--- a/src/k_menudraw.c
+++ b/src/k_menudraw.c
@@ -4711,8 +4711,8 @@ static void M_DrawChallengeTile(INT16 i, INT16 j, INT32 x, INT32 y, boolean hili
 			case SECRET_CUP:
 				categoryid = '4';
 				break;
-			//case SECRET_MASTERBOTS:
 			case SECRET_HARDSPEED:
+			case SECRET_MASTERMODE:
 			case SECRET_ENCORE:
 				categoryid = '5';
 				break;
@@ -4773,12 +4773,12 @@ static void M_DrawChallengeTile(INT16 i, INT16 j, INT32 x, INT32 y, boolean hili
 				break;
 			}
 
-			/*case SECRET_MASTERBOTS:
-				iconid = 4;
-				break;*/
 			case SECRET_HARDSPEED:
 				iconid = 3;
 				break;
+			case SECRET_MASTERMODE:
+				iconid = 4;
+				break;
 			case SECRET_ENCORE:
 				iconid = 5;
 				break;
@@ -5026,6 +5026,16 @@ static void M_DrawChallengePreview(INT32 x, INT32 y)
 			specialmap = hardmapcache;
 			break;
 		}
+		case SECRET_MASTERMODE:
+		{
+			static UINT16 mastermapcache = NEXTMAP_INVALID;
+			if (mastermapcache > nummapheaders)
+			{
+				mastermapcache = G_RandMap(G_TOLFlag(GT_RACE), -1, 2, 0, false, NULL);
+			}
+			specialmap = mastermapcache;
+			break;
+		}
 		case SECRET_ALTTITLE:
 		{
 			x = 8;
@@ -5066,6 +5076,13 @@ static void M_DrawChallengePreview(INT32 x, INT32 y)
 			W_CachePatchName(K_GetItemPatch(KITEM_ROCKETSNEAKER, false), PU_CACHE),
 			NULL);
 	}
+	else if (ref->type == SECRET_MASTERMODE)
+	{
+		V_DrawFixedPatch((x+40-25)<<FRACBITS, ((y+25-25)<<FRACBITS),
+			FRACUNIT, 0,
+			W_CachePatchName(K_GetItemPatch(KITEM_JAWZ, false), PU_CACHE),
+			NULL);
+	}
 	else
 	{
 		colormap = R_GetTranslationColormap(TC_DEFAULT, cv_playercolor[0].value, GTC_MENUCACHE);
diff --git a/src/m_cond.h b/src/m_cond.h
index 367f3d720..01f055758 100644
--- a/src/m_cond.h
+++ b/src/m_cond.h
@@ -119,8 +119,8 @@ typedef enum
 
 	// Difficulty restrictions
 	SECRET_HARDSPEED,			// Permit Hard gamespeed
+	SECRET_MASTERMODE,			// Permit Master Mode bots in GP
 	SECRET_ENCORE,				// Permit Encore option
-	SECRET_LEGACYBOXRUMMAGE,	// Permit the Legacy Box for record attack, etc
 
 	// Menu restrictions
 	SECRET_TIMEATTACK,			// Permit Time attack