diff --git a/src/subsystems/inventory_subsystem/inventory_subsystem.rs b/src/subsystems/inventory_subsystem/inventory_subsystem.rs
new file mode 100644
index 0000000..7e685dd
--- /dev/null
+++ b/src/subsystems/inventory_subsystem/inventory_subsystem.rs
@@ -0,0 +1,83 @@
+use std::sync::{Arc, mpsc};
+
+use crate::server::IpcMessage;
+use crate::{DatabaseManager, JsonManager};
+
+#[macro_use]
+use packet_processor::*;
+
+pub struct InventorySubsystem {
+    packets_to_send_tx: mpsc::Sender<IpcMessage>,
+    db: Arc<DatabaseManager>,
+    jm: Arc<JsonManager>,
+}
+
+impl InventorySubsystem {
+    pub fn new(jm: Arc<JsonManager>, db: Arc<DatabaseManager>, packets_to_send_tx: mpsc::Sender<IpcMessage>) -> Self {
+        Self {
+            packets_to_send_tx: packets_to_send_tx.clone(),
+            db: db.clone(),
+            jm: jm.clone(),
+        }
+    }
+
+    pub fn add_item(&self,  user_id: u32, metadata: &proto::PacketHead, item_id: u32, count: u32, reason: &proto::ActionReasonType, inform_user: bool) {
+        let (item, is_new) = if self.jm.is_item_weapon(item_id) || self.jm.is_item_reliquary(item_id) {
+            assert!(count == 1);
+            (self.db.add_equip(user_id, item_id).unwrap(), false) // TODO: is new equip considered a new item?
+        } else {
+            let old_count = self.db.get_item_count_by_item_id(user_id, item_id);
+
+            (self.db.add_stackable(user_id, item_id, count as i32).unwrap(), old_count == 0)
+        };
+
+        if inform_user {
+            build_and_send!(self, user_id, metadata, ItemAddHintNotify {
+                item_list: vec![build!(ItemHint {
+                    item_id: item_id,
+                    count: count,
+                    is_new: is_new,
+                })],
+                reason: *reason as u32,
+            });
+        }
+
+        build_and_send!(self, user_id, metadata, StoreItemChangeNotify {
+            store_type: proto::StoreType::StorePack as i32, // TODO: hardcoded!
+            item_list: vec![item],
+        });
+    }
+
+    pub fn sub_item(&self,  user_id: u32, metadata: &proto::PacketHead, item_id: u32, count: u32, reason: &proto::ActionReasonType) {
+        let old_amount = self.db.get_item_count_by_item_id(user_id, item_id);
+
+        assert!(old_amount >= count);
+
+        let (new_amount, item) = if self.jm.is_item_weapon(item_id) || self.jm.is_item_reliquary(item_id) {
+            panic!("You can't 'substract' a weapon or reliquary {}!", item_id)
+        } else {
+            let item = if old_amount > count {
+                // Just "add" a negative amount of items
+                self.db.add_stackable(user_id, item_id, -(count as i32)).unwrap()
+            } else {
+                self.db.remove_item_by_item_id(user_id, item_id).unwrap()
+            };
+
+            (old_amount - count, item)
+        };
+
+        if new_amount > 0 {
+            assert!(item.detail != None);
+
+            build_and_send!(self, user_id, metadata, StoreItemChangeNotify {
+                store_type: proto::StoreType::StorePack as i32,
+                item_list: vec![item],
+            });
+        } else {
+            build_and_send!(self, user_id, metadata, StoreItemDelNotify {
+                store_type: proto::StoreType::StorePack as i32, // TODO: hardcoded!
+                guid_list: vec![item.guid],
+            });
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/subsystems/inventory_subsystem/mod.rs b/src/subsystems/inventory_subsystem/mod.rs
new file mode 100644
index 0000000..2ed2620
--- /dev/null
+++ b/src/subsystems/inventory_subsystem/mod.rs
@@ -0,0 +1,3 @@
+mod inventory_subsystem;
+
+pub use self::inventory_subsystem::InventorySubsystem;
\ No newline at end of file
diff --git a/src/subsystems/mod.rs b/src/subsystems/mod.rs
index 2330e39..d12aa00 100644
--- a/src/subsystems/mod.rs
+++ b/src/subsystems/mod.rs
@@ -1,6 +1,8 @@
 pub mod entity_subsystem;
+pub mod inventory_subsystem;
 pub mod misc;
 
 pub use self::entity_subsystem::EntitySubsystem;
+pub use self::inventory_subsystem::InventorySubsystem;
 pub use self::misc::NpcSubsystem;
 pub use self::misc::ShopSubsystem;
\ No newline at end of file