diff --git a/server/gameserver/creature.cc b/server/gameserver/creature.cc
index bbeca63e..7d4d7080 100644
--- a/server/gameserver/creature.cc
+++ b/server/gameserver/creature.cc
@@ -981,6 +981,11 @@ void Creature::DoSkill(int skill_id,
         context_dir = skill_dir_;
         context_pos = GetPos();
         context_pos.AddGlmVec3(skill_dir_ * skill_distance_);
+#ifdef DEBUG
+        if (IsPlayer()) {
+            a8::XPrintf("skill-distance:%f\n", {skill_distance_});
+        }
+#endif
         CurrentSkill()->last_use_frameno = room->GetFrameNo();
         skill->LockCastPhase();
         if (CurrentSkill()->meta->skill_target() == kST_Self
@@ -3558,3 +3563,8 @@ void Creature::SetLastAttacker(CreatureWeakPtr attacker)
     last_attacker_revive_times_ = attacker.Get()->revive_count;
     last_beattack_frameno_ = room->GetFrameNo();
 }
+
+void Creature::ActivateTargetValidPos()
+{
+
+}
diff --git a/server/gameserver/creature.h b/server/gameserver/creature.h
index 111f6ed9..23068829 100644
--- a/server/gameserver/creature.h
+++ b/server/gameserver/creature.h
@@ -106,6 +106,8 @@ class Creature : public MoveableEntity
     Weapon second_weapon;
     glm::vec3 skill_pos;
     Position context_pos;
+    bool target_valid_pos_activated = false;
+    glm::vec3 target_valid_pos = GlmHelper::ZERO;
     glm::vec3 context_real_pos = GlmHelper::ZERO;
     glm::vec3 context_dir = GlmHelper::ZERO;
     std::shared_ptr<Ability> context_ability;
@@ -378,6 +380,7 @@ class Creature : public MoveableEntity
     CreatureWeakPtr& GetLastAttacker() { return last_attacker_; }
     long long GetLastBeAttackFrameNo() { return last_beattack_frameno_; }
     int GetLastAttackerReviveTimes() { return last_attacker_revive_times_; }
+    void ActivateTargetValidPos();
 
 protected:
     virtual void OnBuffRemove(Buff& buff);
diff --git a/server/gameserver/lispenv.cc b/server/gameserver/lispenv.cc
index f2abd7b2..50239889 100644
--- a/server/gameserver/lispenv.cc
+++ b/server/gameserver/lispenv.cc
@@ -229,6 +229,41 @@ public:
                  }
                  return std::make_shared<a8::lisp::Value>(a8::lisp::Atom(result));
              });
+
+        RegisterCProc
+            (
+             "caster.get_skill_target_valid_pos_x",
+             [this] (const a8::lisp::List& params) -> std::shared_ptr<a8::lisp::Value>
+             {
+                 double result = 0.0f;
+                 if (context_.buff->GetCaster().Get()) {
+                     result = context_.buff->GetCaster().Get()->context_pos.GetX();
+                 }
+                 return std::make_shared<a8::lisp::Value>(a8::lisp::Atom(result));
+             });
+        RegisterCProc
+            (
+             "caster.get_skill_target_valid_pos_y",
+             [this] (const a8::lisp::List& params) -> std::shared_ptr<a8::lisp::Value>
+             {
+                 double result = 0.0f;
+                 if (context_.buff->GetCaster().Get()) {
+                     result = context_.buff->GetCaster().Get()->context_pos.GetY();
+                 }
+                 return std::make_shared<a8::lisp::Value>(a8::lisp::Atom(result));
+             });
+        RegisterCProc
+            (
+             "caster.get_skill_target_valid_pos_z",
+             [this] (const a8::lisp::List& params) -> std::shared_ptr<a8::lisp::Value>
+             {
+                 double result = 0.0f;
+                 if (context_.buff->GetCaster().Get()) {
+                     result = context_.buff->GetCaster().Get()->context_pos.GetZ();
+                 }
+                 return std::make_shared<a8::lisp::Value>(a8::lisp::Atom(result));
+             });
+
         RegisterCProc
             (
              "caster.get_hero_atk",