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+# ER and attributes for combat
+
+![](./ER_for_combat.png)
+
+### Entity
+A Battle has a Battle Number (the primary key) and Date(BattleDate) attribute.
+
+A Combat has a Damage, Weapon and a Result attribute.
+
+### Relationship: Involved (battle)
+A combat must have battle involved.
+
+A battle will contain at least on combat.
+
+### Relationship: Involved (Attacker / Defender)
+A combat must have at least 1 characters involved.
+
+A Characters may contain empty combat history
+
+# ER and attributes for characters
+
+![](./ER_for_characters.png)
+
+### Entity
+
+A Characters has a Name(key)​, Type, Level, ExperiencePoints, MaxHealth, Health, AttackInScore, DefenceScore, StealthScore, ManaScore, MoneyBank MoneyWallet attribute.
+
+
+### Relationship: OwnedBy
+A character must owned by one player
+
+A player may have many characters
+
+### Relationship: OwnItems
+An Items must owned by one character
+
+A character may have many Items
+
+If a character is deleted from the game server, the items will be deleted
+
+### Relationship: Involved
+
+A Combat (either attacker/defender) must owned by one character
+
+A character may involved in many combats
+
+If a character is deleted from the game server, the combat will be deleted
+
+
+# ER and attributes for customers/players
+
+![](./ER_for_customers.png)
+
+
+## Entity set
+
+A customers has a AccountNumber(key)​, Name and EMailAddress attribute.
+
+Name is a Multi-valued attribute containing Forename and Surname.
+
+## Relationship Owned By
+
+A Characters must owned by one character
+
+A customers/player may have many character
+
+If a customer/player is deleted from the game server, the characters will be deleted
+
+# ER and attributes for items/inventory
+
+![](./ER_for_items.png)
+
+## Entity set
+
+A Items has a ItemName, ItemType, WeaponType, Quantity, Range, SingleUse, Price, Equipped, BodyPart, Wearable, Worn attribute
+
+A Score is a Multi-valued attribute containing ManaScore, DefendScore and AttackScore.
+
+A ItemKey is an key to indicate the specific item
+
+## Relationship OwnedItems
+
+A Items must owned by one character
+
+A character may have many items
+
+If a character is deleted from the game server, the Items will be deleted
+
+
+# Overview of ERs
+
+![](./ER_overview.png)