public boolean wearFromInventory(int invSlot) {
        final Item wear = inv.get(invSlot);
        if (wear == null) {
            return false;
        }
        EquipmentType type = getType(wear);
        final Item worn = get(type.slot);

        if (worn != null && worn.id == wear.id) {

            if (!ItemDef.forId(worn.id).isStackable()) {
                return false;
            }
            long totalAmount = worn.amt + wear.amt;
            if (totalAmount > MAX_ITEM_AMT) {
                inv.set(Item.valueOf(worn.id, (int) (totalAmount - MAX_ITEM_AMT)), invSlot);
                set(Item.valueOf(worn.id, MAX_ITEM_AMT), type.slot);
                return true;

            } else {
                set(Item.valueOf(worn.id, inv.del(invSlot).amt + worn.amt), type.slot);
                return true;
            }

        } else {
            set(inv.del(invSlot), type.slot);
        }
        return false;
    }