diff --git a/src/BattleParamsIndex.cc b/src/BattleParamsIndex.cc
index 10fbfd1a..02261b62 100644
--- a/src/BattleParamsIndex.cc
+++ b/src/BattleParamsIndex.cc
@@ -20,7 +20,7 @@ void BattleParamsIndex::Table::print(FILE* stream) const {
         e.char_stats.dfp.load(),
         e.char_stats.ata.load(),
         e.char_stats.lck.load(),
-        e.unknown_a1.load(),
+        e.esp.load(),
         e.experience.load(),
         e.meseta.load());
   };
diff --git a/src/Client.cc b/src/Client.cc
index 7659c10d..9a8a5348 100644
--- a/src/Client.cc
+++ b/src/Client.cc
@@ -454,7 +454,7 @@ void Client::create_battle_overlay(shared_ptr<const BattleRules> rules, shared_p
     stats.reset_to_base(char_class, level_table);
     stats.advance_to_level(char_class, target_level, level_table);
 
-    stats.unknown_a1 = 40;
+    stats.esp = 40;
     stats.meseta = 300;
   }
   if (rules->tech_disk_mode == BattleRules::TechDiskMode::LIMIT_LEVEL) {
@@ -500,7 +500,7 @@ void Client::create_challenge_overlay(Version version, size_t template_index, sh
   overlay->disp.stats.reset_to_base(overlay->disp.visual.char_class, level_table);
   overlay->disp.stats.advance_to_level(overlay->disp.visual.char_class, tpl.level, level_table);
 
-  overlay->disp.stats.unknown_a1 = 40;
+  overlay->disp.stats.esp = 40;
   overlay->disp.stats.unknown_a3 = 10.0;
   overlay->disp.stats.experience = level_table->stats_delta_for_level(overlay->disp.visual.char_class, overlay->disp.stats.level).experience;
   overlay->disp.stats.meseta = 0;
diff --git a/src/LevelTable.hh b/src/LevelTable.hh
index ba39cf75..0b076093 100644
--- a/src/LevelTable.hh
+++ b/src/LevelTable.hh
@@ -22,7 +22,7 @@ struct CharacterStats {
 
 struct PlayerStats {
   /* 00 */ CharacterStats char_stats;
-  /* 0E */ le_uint16_t unknown_a1 = 0;
+  /* 0E */ le_uint16_t esp = 0;
   /* 10 */ le_float height = 0.0;
   /* 14 */ le_float unknown_a3 = 0.0;
   /* 18 */ le_uint32_t level = 0;
diff --git a/src/QuestScript.cc b/src/QuestScript.cc
index 74a68d9b..d1331194 100644
--- a/src/QuestScript.cc
+++ b/src/QuestScript.cc
@@ -1507,7 +1507,7 @@ std::string disassemble_quest_script(const void* data, size_t size, Version vers
         lines.emplace_back(string_printf("  %04zX  dfp                  %04hX /* %hu */", l->offset + offsetof(PlayerStats, char_stats.dfp), stats.char_stats.dfp.load(), stats.char_stats.dfp.load()));
         lines.emplace_back(string_printf("  %04zX  ata                  %04hX /* %hu */", l->offset + offsetof(PlayerStats, char_stats.ata), stats.char_stats.ata.load(), stats.char_stats.ata.load()));
         lines.emplace_back(string_printf("  %04zX  lck                  %04hX /* %hu */", l->offset + offsetof(PlayerStats, char_stats.lck), stats.char_stats.lck.load(), stats.char_stats.lck.load()));
-        lines.emplace_back(string_printf("  %04zX  a1                   %04hX /* %hu */", l->offset + offsetof(PlayerStats, unknown_a1), stats.unknown_a1.load(), stats.unknown_a1.load()));
+        lines.emplace_back(string_printf("  %04zX  esp                  %04hX /* %hu */", l->offset + offsetof(PlayerStats, esp), stats.esp.load(), stats.esp.load()));
         lines.emplace_back(string_printf("  %04zX  height               %08" PRIX32 " /* %g */", l->offset + offsetof(PlayerStats, height), stats.height.load_raw(), stats.height.load()));
         lines.emplace_back(string_printf("  %04zX  a3                   %08" PRIX32 " /* %g */", l->offset + offsetof(PlayerStats, unknown_a3), stats.unknown_a3.load_raw(), stats.unknown_a3.load()));
         lines.emplace_back(string_printf("  %04zX  level                %08" PRIX32 " /* level %" PRIu32 " */", l->offset + offsetof(PlayerStats, level), stats.level.load(), stats.level.load() + 1));