Prevent bypassing demon boss lairs via level teleport.

Now that the player no longer needs to come back up through Gehennom for
the ascension run, it became possible for the player to skip all of the
demon bosses altogether via levelporting past their lairs. You could do
this before Purgatory was introduced, but you still had to come back up
with the Amulet of Yendor/imbued Idol of Moloch, and teleportation is
suppressed at that point. This patch prevents levelporting past the
demon boss lairs. If the player tries to levelport past them, they'll
land on each demon boss level instead. And because using teleportation
on yourself is greatly supressed while that demon boss is alive, it
virtually guarantees each demon boss having to be dealt with.

Author: k21971

doc/evilhack-changelog.md

@@ -2682,4 +2682,5 @@ The following changes to date are:
 
 - Latest merges from 'vanilla' NetHack 3.6.6 official release (as of January 23rd, 2022)
 - Initial preparation for new version (0.8.2)
+- Prevent bypassing demon boss lairs via level teleport
 

include/dungeon.h

@@ -118,6 +118,7 @@ typedef struct branch {
 #define Is_hella_level(x)     (Lcheck(x, &hella_level))
 #define Is_hellb_level(x)     (Lcheck(x, &hellb_level))
 #define Is_hellc_level(x)     (Lcheck(x, &hellc_level))
+#define Is_orcustown(x)       (Lcheck(x, &orcus_level))
 #define Is_wiz1_level(x)      (Lcheck(x, &wiz1_level))
 #define Is_wiz2_level(x)      (Lcheck(x, &wiz2_level))
 #define Is_wiz3_level(x)      (Lcheck(x, &wiz3_level))

include/you.h

@@ -49,7 +49,10 @@ struct u_event {
     Bitfield(invoked, 1);           /* invoked Gate to the Sanctum level */
     Bitfield(gehennom_entered, 1);  /* entered Gehennom via Valley */
     Bitfield(tower_entered, 1);     /* entered Vlad's tower (cavern level) */
+    Bitfield(hella_entered, 1);     /* entered the first demon lord lair */
+    Bitfield(hellb_entered, 1);     /* entered the second demon lord lair */
     Bitfield(hellc_entered, 1);     /* entered one of the demon prince lairs */
+    Bitfield(orcus_entered, 1);     /* entered Orcus town */
     Bitfield(iceq_entered, 1);      /* entered the Ice Queen's realm */
     Bitfield(vecnad_entered, 1);    /* entered Vecna's domain */
     Bitfield(gtown_entered, 1);     /* entered Goblin Town */

src/do.c

@@ -1884,11 +1884,26 @@ boolean at_stairs, falling, portal;
             com_pager(300);
     }
 
-    /* made it to the final demon boss lair? */
+    /* made it to the first demon lord lair? */
+    if (!Is_hella_level(&u.uz0) && Is_hella_level(&u.uz)
+        && !u.uevent.hella_entered)
+        u.uevent.hella_entered = 1;
+
+    /* made it to the second demon lord lair? */
+    if (!Is_hellb_level(&u.uz0) && Is_hellb_level(&u.uz)
+        && !u.uevent.hellb_entered)
+        u.uevent.hellb_entered = 1;
+
+    /* made it to the final demon prince lair? */
     if (!Is_hellc_level(&u.uz0) && Is_hellc_level(&u.uz)
         && !u.uevent.hellc_entered)
         u.uevent.hellc_entered = 1;
 
+    /* made it to Orcus Town? */
+    if (!Is_orcustown(&u.uz0) && Is_orcustown(&u.uz)
+        && !u.uevent.orcus_entered)
+        u.uevent.orcus_entered = 1;
+
     if (!In_icequeen_branch(&u.uz0) && Iniceq
         && !u.uevent.iceq_entered) {
         u.uevent.iceq_entered = 1;
@@ -1962,7 +1977,7 @@ boolean at_stairs, falling, portal;
 
     /* special location arrival messages/events */
     if (In_endgame(&u.uz)) {
-        if (new &&on_level(&u.uz, &astral_level))
+        if (new && on_level(&u.uz, &astral_level))
             final_level(); /* guardian angel,&c */
         else if (newdungeon && u.uhave.amulet)
             resurrect(); /* force confrontation with Wizard */

src/potion.c

@@ -1127,7 +1127,7 @@ register struct obj *otmp;
             for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
                 /* order is important here, should a demon
                    prince summon a demon lord */
-                if (is_dlord(mtmp->data) && rn2(5)) {
+                if (is_dlord(mtmp->data) && rn2(10)) {
                     pline("Demonic forces prevent you from rising up.");
                     goto no_rise;
                 } else if (is_dprince(mtmp->data) && rn2(20)) {

src/teleport.c

@@ -541,7 +541,7 @@ struct obj *scroll;
     /* Being in the presence of demon lords/princes can negate
        teleportation most of the time */
     for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
-        if (is_dlord(mtmp->data) && rn2(5)
+        if (is_dlord(mtmp->data) && rn2(10)
             && !wizard) {
             pline("Demonic forces prevent you from teleporting.");
             return TRUE;
@@ -852,7 +852,7 @@ level_tele()
     /* Being in the presence of demon lords/princes can negate
        level teleportation most of the time */
     for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
-        if (is_dlord(mtmp->data) && rn2(5)
+        if (is_dlord(mtmp->data) && rn2(10)
             && !wizard) {
             pline("Demonic forces prevent you from teleporting.");
             return;
@@ -1103,11 +1103,24 @@ level_tele()
 
         /* if invocation did not yet occur, teleporting into
          * the last level of Gehennom is forbidden.
+         * attempting to bypass the three demon boss lairs
+         * or Orcus town is also forbidden
          */
-        if (!wizard && Inhell && !u.uevent.invoked && newlev >= deepest) {
-            newlev = deepest - 1;
-            pline("Sorry...");
+        if (!wizard && Inhell) {
+            if (!u.uevent.hella_entered && newlev > depth(&hella_level))
+                newlev = depth(&hella_level);
+            if (!u.uevent.hellb_entered && newlev > depth(&hellb_level))
+                newlev = depth(&hellb_level);
+            if (!u.uevent.hellc_entered && newlev > depth(&hellc_level))
+                newlev = depth(&hellc_level);
+            if (!u.uevent.orcus_entered && newlev > depth(&orcus_level))
+                newlev = depth(&orcus_level);
+            if (!u.uevent.invoked && newlev >= deepest) {
+                newlev = deepest - 1;
+                pline("Sorry...");
+            }
         }
+
         /* no teleporting out of quest dungeon */
         if (In_quest(&u.uz) && newlev < depth(&qstart_level))
             newlev = depth(&qstart_level);