Civilization – What tile types does vitalize upgrade, and to what tiles

Advantages:

• you get access to that resource if you have the right tech (so it can be a good idea to build a city on strategically important resources like iron, oil, etc. - they will be better protected from spies and enemy units).

• you don't need to wait several turns until the worker builds the improvement.

• in fact resources DO give some kind of tile bonus if you build a city on them. This means +1 Commerce for Commerce Resources (Dye, Gold, etc.), +1 Food for Food Resources (Pig, Wheat, etc., but only on plain terrain, not hills), +1 Hammer for Production Resources (Iron, Ivory, etc. BUT +2 on hills). Even though these numbers seem to be small, in the beginning it can still be a big boost to a new city.

Disadvantages:

• you cannot build improvements on the resource, so in the long run you lose the huge hammer/commerce/food bonuses that would result from the improvement.

Roads have two primary functions:

• They reduce the costs to move units (i.e. your units can walk further if they're walking on roads; like hills vs. grassland).

• They establish trade routes between cities on land (this won't work without roads, unless both cities have a port).

• I don't remember any tiles requiring roads built (but feel free to correct me).