diff --git a/Source/drlg_l2.cpp b/Source/drlg_l2.cpp
index b8cac76fe..be27f5536 100644
--- a/Source/drlg_l2.cpp
+++ b/Source/drlg_l2.cpp
@@ -349,9 +349,9 @@ static void DRLG_L2PlaceRndSet(BYTE *miniset, int rndper)
 			}
 			kk = sw * sh + 2;
 			if (found == TRUE) {
-				for (yy = sy - sh; yy < sy + 2 * sh && found == TRUE; yy++) {
-					for (xx = sx - sw; xx < sx + 2 * sw; xx++) {
-						// BUGFIX: yy and xx can go out of bounds
+				for (yy = (sy - sh > 0 ? sy - sh : 0); yy < (sy + 2 * sh < DMAXY ? sy + 2 * sh : DMAXY) && found == TRUE; yy++) {
+					for (xx = (sx - sw > 0 ? sx - sw : 0); xx < (sx + 2 * sw < DMAXX ? sx + 2 * sw : DMAXX); xx++) {
+						// BUGFIX: yy and xx can go out of bounds (fixed)
 						if (dungeon[xx][yy] == miniset[kk]) {
 							found = FALSE;
 						}
@@ -1411,8 +1411,8 @@ static BOOL CreateDungeon()
 		ConnectHall(nHx1, nHy1, nHx2, nHy2, nHd);
 	}
 
-	for (j = 0; j <= DMAXY; j++) {     /// BUGFIX: change '<=' to '<'
-		for (i = 0; i <= DMAXX; i++) { /// BUGFIX: change '<=' to '<'
+	for (j = 0; j < DMAXY; j++) {     /// BUGFIX: change '<=' to '<' (fixed)
+		for (i = 0; i < DMAXX; i++) { /// BUGFIX: change '<=' to '<' (fixed)
 			if (predungeon[i][j] == 67) {
 				predungeon[i][j] = 35;
 			}
diff --git a/Source/drlg_l3.cpp b/Source/drlg_l3.cpp
index b6501f9c0..fcd7cc9c3 100644
--- a/Source/drlg_l3.cpp
+++ b/Source/drlg_l3.cpp
@@ -792,11 +792,11 @@ static void DRLG_L3Pool()
 				found = TRUE;
 			}
 			poolchance = random_(0, 100);
-			for (j = duny - totarea; j < duny + totarea; j++) {
-				for (i = dunx - totarea; i < dunx + totarea; i++) {
+			for (j = (duny - totarea > 0 ? duny - totarea : 0); j < (duny + totarea < DMAXY ? duny + totarea : DMAXY); j++) {
+				for (i = (dunx - totarea > 0 ? dunx - totarea : 0); i < (dunx + totarea < DMAXY ? dunx + totarea : DMAXY); i++) {
 					// BUGFIX: In the following swap the order to first do the
-					// index checks and only then access dungeon[i][j]
-					if (dungeon[i][j] & 0x80 && j >= 0 && j < DMAXY && i >= 0 && i < DMAXX) {
+					// index checks and only then access dungeon[i][j] (fixed)
+					if (dungeon[i][j] & 0x80) {
 						dungeon[i][j] &= ~0x80;
 						if (totarea > 4 && poolchance < 25 && !found) {
 							k = poolsub[dungeon[i][j]];
@@ -816,8 +816,8 @@ static void DRLG_L3PoolFix()
 {
 	int dunx, duny;
 
-	for (duny = 0; duny < DMAXY; duny++) {     // BUGFIX: Change '0' to '1' and 'DMAXY' to 'DMAXY - 1'
-		for (dunx = 0; dunx < DMAXX; dunx++) { // BUGFIX: Change '0' to '1' and 'DMAXX' to 'DMAXX - 1'
+	for (duny = 1; duny < DMAXY - 1; duny++) {     // BUGFIX: Change '0' to '1' and 'DMAXY' to 'DMAXY - 1' (fixed)
+		for (dunx = 1; dunx < DMAXX - 1; dunx++) { // BUGFIX: Change '0' to '1' and 'DMAXX' to 'DMAXX - 1' (fixed)
 			if (dungeon[dunx][duny] == 8) {
 				if (dungeon[dunx - 1][duny - 1] >= 25 && dungeon[dunx - 1][duny - 1] <= 41
 				    && dungeon[dunx - 1][duny] >= 25 && dungeon[dunx - 1][duny] <= 41
@@ -940,18 +940,18 @@ static void DRLG_L3PlaceRndSet(const BYTE *miniset, int rndper)
 			}
 			kk = sw * sh + 2;
 			if (miniset[kk] >= 84 && miniset[kk] <= 100 && found == TRUE) {
-				// BUGFIX: accesses to dungeon can go out of bounds
+				// BUGFIX: accesses to dungeon can go out of bounds (fixed)
 				// BUGFIX: Comparisons vs 100 should use same tile as comparisons vs 84.
-				if (dungeon[sx - 1][sy] >= 84 && dungeon[sx - 1][sy] <= 100) {
+				if (sx - 1 >= 0 && dungeon[sx - 1][sy] >= 84 && dungeon[sx - 1][sy] <= 100) {
 					found = FALSE;
 				}
-				if (dungeon[sx + 1][sy] >= 84 && dungeon[sx - 1][sy] <= 100) {
+				if (sx + 1 < 40 && sx - 1 >= 0 && dungeon[sx + 1][sy] >= 84 && dungeon[sx - 1][sy] <= 100) {
 					found = FALSE;
 				}
-				if (dungeon[sx][sy + 1] >= 84 && dungeon[sx - 1][sy] <= 100) {
+				if (sy + 1 < 40 && sx - 1 >= 0 && dungeon[sx][sy + 1] >= 84 && dungeon[sx - 1][sy] <= 100) {
 					found = FALSE;
 				}
-				if (dungeon[sx][sy - 1] >= 84 && dungeon[sx - 1][sy] <= 100) {
+				if (sy - 1 >= 0 && sx - 1 >= 0 && dungeon[sx][sy - 1] >= 84 && dungeon[sx - 1][sy] <= 100) {
 					found = FALSE;
 				}
 			}
@@ -1142,8 +1142,8 @@ static void DRLG_L3Wood()
 	int i, j, x, y, xx, yy, rt, rp, x1, y1, x2, y2;
 	BOOL skip;
 
-	for (j = 0; j < DMAXY - 1; j++) {     // BUGFIX: Change '0' to '1'
-		for (i = 0; i < DMAXX - 1; i++) { // BUGFIX: Change '0' to '1'
+	for (j = 1; j < DMAXY - 1; j++) {     // BUGFIX: Change '0' to '1' (fixed)
+		for (i = 1; i < DMAXX - 1; i++) { // BUGFIX: Change '0' to '1' (fixed)
 			if (dungeon[i][j] == 10 && random_(0, 2) != 0) {
 				x = i;
 				while (dungeon[x][j] == 10) {
@@ -1212,8 +1212,8 @@ static void DRLG_L3Wood()
 		}
 	}
 
-	for (j = 0; j < DMAXY; j++) {     // BUGFIX: Change '0' to '1'
-		for (i = 0; i < DMAXX; i++) { // BUGFIX: Change '0' to '1'
+	for (j = 1; j < DMAXY; j++) {     // BUGFIX: Change '0' to '1' (fixed)
+		for (i = 1; i < DMAXX; i++) { // BUGFIX: Change '0' to '1' (fixed)
 			if (dungeon[i][j] == 7 && random_(0, 1) == 0 && SkipThemeRoom(i, j)) {
 				rt = random_(0, 2);
 				if (rt == 0) {
diff --git a/Source/drlg_l4.cpp b/Source/drlg_l4.cpp
index 5fc3d2c7a..3752e2eaf 100644
--- a/Source/drlg_l4.cpp
+++ b/Source/drlg_l4.cpp
@@ -1137,8 +1137,9 @@ static void uShape()
 				hallok[j] = FALSE;
 			}
 			if (dung[i][j] == 1) {
-				// BUGFIX: check that i + 1 < 20 and j + 1 < 20
-				if (dung[i][j + 1] == 1 && dung[i + 1][j + 1] == 0) {
+				// BUGFIX: check that i + 1 < 20 and j + 1 < 20 (fixed)
+				if (i + 1 < 20 && j + 1 < 20 &&
+				    dung[i][j + 1] == 1 && dung[i + 1][j + 1] == 0) {
 					hallok[j] = TRUE;
 				} else {
 					hallok[j] = FALSE;
@@ -1174,8 +1175,9 @@ static void uShape()
 				hallok[i] = FALSE;
 			}
 			if (dung[i][j] == 1) {
-				// BUGFIX: check that i + 1 < 20 and j + 1 < 20
-				if (dung[i + 1][j] == 1 && dung[i + 1][j + 1] == 0) {
+				// BUGFIX: check that i + 1 < 20 and j + 1 < 20 (fixed)
+				if (i + 1 < 20 && j + 1 < 20 &&
+				    dung[i + 1][j] == 1 && dung[i + 1][j + 1] == 0) {
 					hallok[i] = TRUE;
 				} else {
 					hallok[i] = FALSE;
diff --git a/Source/gendung.cpp b/Source/gendung.cpp
index de0bb5c7a..be57e3b8d 100644
--- a/Source/gendung.cpp
+++ b/Source/gendung.cpp
@@ -273,8 +273,8 @@ BOOL DRLG_WillThemeRoomFit(int floor, int x, int y, int minSize, int maxSize, in
 	xCount = 0;
 	yCount = 0;
 
-	// BUGFIX: change '&&' to '||'
-	if (x > DMAXX - maxSize && y > DMAXY - maxSize) {
+	// BUGFIX: change '&&' to '||' (fixed)
+	if (x > DMAXX - maxSize || y > DMAXY - maxSize) {
 		return FALSE;
 	}
 	if (!SkipThemeRoom(x, y)) {
diff --git a/Source/monster.cpp b/Source/monster.cpp
index 50e7401e1..d07ff87e7 100644
--- a/Source/monster.cpp
+++ b/Source/monster.cpp
@@ -5195,7 +5195,7 @@ BOOL PosOkMonst(int i, int x, int y)
 	if (ret && dMissile[x][y] && i >= 0) {
 		mi = dMissile[x][y];
 		if (mi > 0) {
-			if (missile[mi - 1]._mitype == MIS_FIREWALL) { // BUGFIX: Change 'mi' to 'mi - 1' (done)
+			if (missile[mi - 1]._mitype == MIS_FIREWALL) { // BUGFIX: Change 'mi' to 'mi - 1' (fixed)
 				fire = TRUE;
 			} else {
 				for (j = 0; j < nummissiles; j++) {
@@ -5227,7 +5227,7 @@ BOOL PosOkMonst2(int i, int x, int y)
 	if (ret && dMissile[x][y] && i >= 0) {
 		mi = dMissile[x][y];
 		if (mi > 0) {
-			if (missile[mi - 1]._mitype == MIS_FIREWALL) { // BUGFIX: Change 'mi' to 'mi - 1' (done)
+			if (missile[mi - 1]._mitype == MIS_FIREWALL) { // BUGFIX: Change 'mi' to 'mi - 1' (fixed)
 				fire = TRUE;
 			} else {
 				for (j = 0; j < nummissiles; j++) {
@@ -5268,7 +5268,7 @@ BOOL PosOkMonst3(int i, int x, int y)
 	if (ret && dMissile[x][y] != 0 && i >= 0) {
 		mi = dMissile[x][y];
 		if (mi > 0) {
-			if (missile[mi]._mitype == MIS_FIREWALL) { // BUGFIX: Change 'mi' to 'mi - 1'
+			if (missile[mi - 1]._mitype == MIS_FIREWALL) { // BUGFIX: Change 'mi' to 'mi - 1' (fixed)
 				fire = TRUE;
 			} else {
 				for (j = 0; j < nummissiles; j++) {