Apart from providing a resource needed to advance the level of a Town, many Resources also give some special benefit to the player for owning that Resource.
A Resource special effect could apply to all towns within the territory of the town producing the Resource. For example, producing BOATS would allow Resources to be exported across bodies of water, but only from (player-owned) Towns within the Fief/Barony/County/Duchy/Kingdom/Empire of the Town producing BOATS.
Other special effects could be available as well. Perhaps a "Wild Card" Resource which can act as any other resource for level-up requirements. ORE exported to a BLACKSMITH Town could enhance the effectiveness of that Blacksmith. Or many other things.
Keep it simple though...
Apart from providing a resource needed to advance the level of a Town, many Resources also give some special benefit to the player for owning that Resource.
A Resource special effect could apply to all towns within the territory of the town producing the Resource. For example, producing BOATS would allow Resources to be exported across bodies of water, but only from (player-owned) Towns within the Fief/Barony/County/Duchy/Kingdom/Empire of the Town producing BOATS.
Other special effects could be available as well. Perhaps a "Wild Card" Resource which can act as any other resource for level-up requirements. ORE exported to a BLACKSMITH Town could enhance the effectiveness of that Blacksmith. Or many other things. Keep it simple though...