Player Charm: new effect (WIP)

Allow monsters to finally get to use a wand of charming on the player.

Previously monsters could use the wand but would never use it on the
player; only on their allies. This made it useless against anyone not
using allies, and even then exploitable by just leaving allies behind
when facing one. Consequently it was not such a high-tier threat even
though it could be (compared to how useful it is to a player).

The new effect is designed to be a serious threat, especially from a
monster that already has a pack of their own allies, as well as
attempting to be mechanically distinct from other debuffs that tread
similar "mind control" territory (e.g. Mesmerisation or Fear).

A successful use will make all *same-species* (TBD) monsters in LOS gain a
"charmer" status, with a new pink halo as it's fundamentally an
alignment change (from the player's perspective).

You are tricked into thinking these monsters are your friends, and your
allies will now also consider them aligned (TBD). You can attempt to
attack them but will now receive a warning much like when attempting
to attack allies, as 25% (TBD) of any damage you cause them will now be
reflected back sympathetically onto yourself, although this will not
kill you directly.

On attacking (or being attacked by) any "charmer" monster you will make
another willpower check (with considerably worse chances than the
initial enchantment roll) to break free of their glamour. This simulates
you fighting against your own will to regain control of your faculties.

This gives the player rather more agency and decision-making in dealing
with the threat (it's even worth taking a resistance potion *after*
being charmed as it will help with subsequent will checks).
(TBD how curing / quicksilver / yara's work).

crawl-ref/source/beam.cc

@@ -3722,9 +3722,11 @@ void bolt::affect_player_enchantment(bool resistible)
 
     case BEAM_CHARM:
         mprf(MSGCH_WARN, "Your will is overpowered!");
-        confuse_player(5 + random2(3));
+        // Double original effective spell power to be used on escape checks
+        // (degree will decay with the enchantment though)
+        you.charm(agent(), ench_power * 2);
         obvious_effect = true;
-        break;     // charming - confusion?
+        break;
 
     case BEAM_BANISH:
         if (YOU_KILL(thrower))
@@ -4690,7 +4692,8 @@ void bolt::handle_stop_attack_prompt(monster* mon)
     {
         string adj, suffix;
         bool penance;
-        if (bad_attack(mon, adj, suffix, penance, target))
+        bool self_hurt;
+        if (bad_attack(mon, adj, suffix, penance, self_hurt, target))
             friendly_past_target = true;
         return;
     }

crawl-ref/source/enchant-type.h

@@ -228,6 +228,7 @@ enum enchant_type
     ENCH_CHANGED_APPEARANCE,  // Visual change for player shadow during Shadowslip
     ENCH_SHADOWLESS,
     ENCH_AMNESIA,
+    ENCH_CHARMER,
     // Update enchant_names[] in mon-ench.cc when adding or removing
     // enchantments.
     NUM_ENCHANTMENTS

crawl-ref/source/fight.cc

@@ -1233,7 +1233,8 @@ int mons_weapon_damage_rating(const item_def &launcher)
 }
 
 bool bad_attack(const monster *mon, string& adj, string& suffix,
-                bool& would_cause_penance, coord_def attack_pos)
+                bool& would_cause_penance, bool& could_self_hurt,
+                coord_def attack_pos)
 {
     ASSERT(mon); // XXX: change to const monster &mon
     ASSERT(!crawl_state.game_is_arena());
@@ -1247,10 +1248,18 @@ bool bad_attack(const monster *mon, string& adj, string& suffix,
     adj.clear();
     suffix.clear();
     would_cause_penance = false;
+    could_self_hurt = false;
 
     if (is_sanctuary(mon->pos()) || is_sanctuary(attack_pos))
         suffix = ", despite your sanctuary";
 
+    if (mon->has_ench(ENCH_CHARMER))
+    {
+        adj = "your \"friend\" ";
+        could_self_hurt = true;
+        return true;
+    }
+
     if (mon->friendly())
     {
         // There's not really any harm in attacking your own spectral weapon.
@@ -1271,7 +1280,6 @@ bool bad_attack(const monster *mon, string& adj, string& suffix,
                 adj += "the ";
 
             would_cause_penance = true;
-
         }
         else
         {
@@ -1313,6 +1321,7 @@ bool stop_attack_prompt(const monster* mon, bool beam_attack,
 {
     ASSERT(mon); // XXX: change to const monster &mon
     bool penance = false;
+    bool self_hurt = false;
 
     if (prompted)
         *prompted = false;
@@ -1327,7 +1336,7 @@ bool stop_attack_prompt(const monster* mon, bool beam_attack,
         return false;
 
     string adj, suffix;
-    if (!bad_attack(mon, adj, suffix, penance, attack_pos))
+    if (!bad_attack(mon, adj, suffix, penance, self_hurt, attack_pos))
         return false;
 
     // We have already determined this attack *would* prompt, so stop here
@@ -1356,9 +1365,10 @@ bool stop_attack_prompt(const monster* mon, bool beam_attack,
     else
         verb = "attack ";
 
-    const string prompt = make_stringf("Really %s%s%s?%s",
+    const string prompt = make_stringf("Really %s%s%s?%s%s",
              verb.c_str(), mon_name.c_str(), suffix.c_str(),
-             penance ? " This attack would place you under penance!" : "");
+             penance ? " This attack would place you under penance!" : "",
+             self_hurt ? " You might inflict damage on yourself!" : "");
 
     if (prompted)
         *prompted = true;
@@ -1407,7 +1417,8 @@ bool stop_attack_prompt(targeter &hitfunc, const char* verb,
 
         string adjn, suffixn;
         bool penancen = false;
-        if (bad_attack(mon, adjn, suffixn, penancen))
+        bool self_hurt = false;
+        if (bad_attack(mon, adjn, suffixn, penancen, self_hurt))
         {
             // record the adjectives for the first listed, or
             // first that would cause penance

crawl-ref/source/fight.h

@@ -86,7 +86,7 @@ bool player_unrand_bad_attempt(const item_def &weapon,
                                bool check_only);
 
 bool bad_attack(const monster *mon, string& adj, string& suffix,
-                bool& would_cause_penance,
+                bool& would_cause_penance, bool& could_self_hurt,
                 coord_def attack_pos = coord_def(0, 0));
 
 bool stop_attack_prompt(const monster* mon, bool beam_attack,

crawl-ref/source/fineff.cc

@@ -119,6 +119,18 @@ bool deferred_damage_fineff::mergeable(const final_effect &fe) const
            && attacker_effects == o->attacker_effects && fatal == o->fatal;
 }
 
+bool charmer_damage_share_fineff::mergeable(const final_effect &fe) const
+{
+    const charmer_damage_share_fineff *o = dynamic_cast<const charmer_damage_share_fineff *>(&fe);
+    return o && att == o->att && def == o->def;
+}
+
+bool charmer_escape_fineff::mergeable(const final_effect &fe) const
+{
+    const charmer_escape_fineff *o = dynamic_cast<const charmer_escape_fineff *>(&fe);
+    return o && att == o->att && def == o->def;
+}
+
 bool starcursed_merge_fineff::mergeable(const final_effect &fe) const
 {
     const starcursed_merge_fineff *o = dynamic_cast<const starcursed_merge_fineff *>(&fe);
@@ -202,6 +214,24 @@ void deferred_damage_fineff::merge(const final_effect &fe)
     damage += ddamfe->damage;
 }
 
+void charmer_damage_share_fineff::merge(const final_effect &fe)
+{
+    const charmer_damage_share_fineff *ddamfe =
+        dynamic_cast<const charmer_damage_share_fineff *>(&fe);
+    ASSERT(ddamfe);
+    ASSERT(mergeable(*ddamfe));
+    damage += ddamfe->damage;
+}
+
+void charmer_escape_fineff::merge(const final_effect &fe)
+{
+    const charmer_escape_fineff *ddamfe =
+        dynamic_cast<const charmer_escape_fineff *>(&fe);
+    ASSERT(ddamfe);
+    ASSERT(mergeable(*ddamfe));
+    damage += ddamfe->damage;
+}
+
 void shock_discharge_fineff::merge(const final_effect &fe)
 {
     const shock_discharge_fineff *ssdfe =
@@ -432,6 +462,75 @@ void deferred_damage_fineff::fire()
                     true, attacker_effects);
 }
 
+void charmer_damage_share_fineff::fire()
+{
+    // The player has attacked a charming monster takes sympathetic damage
+    actor *source = defender();
+    ASSERT(!source || source->is_monster());
+    monster *charmer = source ? source->as_monster() : nullptr;
+
+    if (!charmer || !charmer->alive())
+        return;
+
+    actor *target = attacker();
+    if (!target || !target->alive())
+        return;
+    ASSERT(target->is_player());
+
+    player *player = attacker()->as_player();
+
+    // Reduce to 1 HP but don't directly kill
+    // XX: Move flavour texts to monster speech
+    damage = min(damage, player->hp - 1);
+    if (charmer)
+    {
+        // Chance to end charming based on your willpower
+        if (player->check_willpower(charmer,
+                                    charmer->get_ench(ENCH_CHARMER).degree))
+        {
+            mprf("You break free of %s mind games!",
+                 apostrophise(charmer->name(DESC_THE)).c_str());
+            charmer->del_ench(ENCH_CHARMER);
+            return;
+        }
+        mprf("You share in the suffering of your friend %s!",
+              charmer->name(DESC_THE).c_str());
+    }
+    else
+        mpr("You anguish over the death of your friend!");
+
+    // Register as player hurting themselves to avoid triggering a bonus
+    // escape fineff (and really the damage was self-inflicted anyway)
+    // XX: Or should the damage be attributable to the monster and use a kill type to prevent recursion?
+    player->hurt(player, damage);
+}
+
+void charmer_escape_fineff::fire()
+{
+    actor *source = attacker();
+    monster *charmer = source ? source->as_monster() : nullptr;
+
+    if (!charmer || !charmer->alive())
+        return;
+
+    actor *target = defender();
+    if (!target || !target->alive())
+        return;
+    ASSERT(target->is_player());
+
+    player *player = target->as_player();
+
+    // Chance to end charming based on your willpower
+    if (player->check_willpower(charmer,
+                                charmer->get_ench(ENCH_CHARMER).degree))
+    {
+        mprf("You break free of %s mind games!",
+             apostrophise(charmer->name(DESC_THE)).c_str());
+        charmer->del_ench(ENCH_CHARMER);
+        return;
+    }
+}
+
 static void _do_merge_masses(monster* initial_mass, monster* merge_to)
 {
     // Combine enchantment durations.

crawl-ref/source/fineff.h

@@ -218,6 +218,48 @@ class deferred_damage_fineff : public final_effect
     bool fatal;
 };
 
+class charmer_damage_share_fineff : public final_effect
+{
+public:
+    bool mergeable(const final_effect &a) const override;
+    void merge(const final_effect &a) override;
+    void fire() override;
+
+    static void schedule(const monster *charmer, int dam)
+    {
+        final_effect::schedule(
+            new charmer_damage_share_fineff(charmer, dam));
+    }
+protected:
+    charmer_damage_share_fineff(const monster *charmer, int dam)
+        : final_effect(&you, charmer, coord_def()),
+          damage(dam)
+    {
+    }
+    int damage;
+};
+
+class charmer_escape_fineff : public final_effect
+{
+public:
+    bool mergeable(const final_effect &a) const override;
+    void merge(const final_effect &a) override;
+    void fire() override;
+
+    static void schedule(const monster *charmer, int dam)
+    {
+        final_effect::schedule(
+            new charmer_escape_fineff(charmer, dam));
+    }
+protected:
+    charmer_escape_fineff(const monster *charmer, int dam)
+        : final_effect(charmer, &you, coord_def()),
+          damage(dam)
+    {
+    }
+    int damage;
+};
+
 class starcursed_merge_fineff : public final_effect
 {
 public:

crawl-ref/source/god-abil.cc

@@ -2529,6 +2529,7 @@ void spare_beogh_convert()
 
         ++witc;
         orc->del_ench(ENCH_CHARM);
+        orc->del_ench(ENCH_CHARMER);
         mons_pacify(*orc, ATT_GOOD_NEUTRAL, true);
     }
 

crawl-ref/source/item-prop.cc

@@ -914,8 +914,8 @@ struct item_set_def
 };
 static const item_set_def item_sets[] =
 {
-    { "hex wand",           OBJ_WANDS,      { WAND_CHARMING, WAND_PARALYSIS } },
-    { "beam wand",          OBJ_WANDS,      { WAND_ACID, WAND_LIGHT, WAND_QUICKSILVER } },
+    { "hex wand",           OBJ_WANDS,      { WAND_CHARMING /*, WAND_PARALYSIS */ } },
+    { "beam wand",          OBJ_WANDS,      { /* WAND_ACID, */ WAND_LIGHT /*, WAND_QUICKSILVER */ } },
     { "blast wand",         OBJ_WANDS,      { WAND_ICEBLAST, WAND_ROOTS, WAND_WARPING } },
     { "ally scroll",        OBJ_SCROLLS,    { SCR_SUMMONING, SCR_BUTTERFLIES } },
     { "area misc",          OBJ_MISCELLANY, { MISC_CONDENSER_VANE,

crawl-ref/source/menu.cc

@@ -2412,6 +2412,8 @@ bool MonsterMenuEntry::get_tiles(vector<tile_def>& tileset) const
         tileset.emplace_back(TILE_HALO_GD_NEUTRAL);
     else if (m->neutral())
         tileset.emplace_back(TILE_HALO_NEUTRAL);
+    else if (m->has_trivial_ench(ENCH_CHARMER))
+        tileset.emplace_back(TILE_HALO_CHARMER);
     else if (Options.tile_show_threat_levels.find("unusual") != string::npos
              && m->has_unusual_items())
         tileset.emplace_back(TILE_THREAT_UNUSUAL);