Help with database model design

[chaplain]

Hi,

I am fairly new to the whole database model design theory. I understand most ( i think) of the relations between entitys but am strugging with my design - Can anybody help suggest how best to do this...

I have four entitys.

[b]games[/b]
  -> game_id  (PK)

[b]maps[/b]
  -> map_id  (PK)

[b]locations[/b]
  -> location_id  (PK)

[b]location_types[/b]
  -> location_type_id  (PK)


What I need to do is...

1) I can have a number of games. Each game will relate to only one map.
2) The location entity can contain locations for all maps so a location needs to know the map it belongs to.
3) The location_type needs to be related to both a map and a location. It will be possible for different locations types to exists for particular maps.

1 and 2 are quite straight forward, its where I add in the location_type where problems start to occur.

Please help - this is really frustraing me

Thanks
Dom