are multiple instances of a resource useful at all?

[krp312]

i know it's good for corporations, but otherwise what're the effects of having like 5 corn sources or something

 

[Refar]

There are none.

Corporations you already listed, otherwise you can trade them. maybe.

 

[Kennigit]

Only for trade purposes.

 

[nbcman]

It also is some protection against pillaging, sabotage missions and random events would cause you to lose one of your sources of the resource. So if you have 2 marble you wont lose the benefit if one of the marble is 'lost' due to the AI sabotaging you.

 

[LlamaCat]

I think the importance of the trade value of having extra resources can't be overstated. This is the key reason to have them. If you are hurting for more happiness, you can trade an extra corn or two to other civs for their extra happiness resources, or vice versa. And you can trade them for money - the AIs will always trade you their maximum allowed gold per turn for any of your extra resources (this is kind of a bug I think, but whatever)... that gold can really add up. This is all assuming you are playing a relatively peaceful game with some other AIs (open borders, etc).

 

[eewallace]

Particularly early in the game, I grab all of the iron, copper and horses that I can see for 2 reasons: (1) to deprive AI civs on them; (2) to have extra in case my primary source gets pillaged.