What BiC said. 4 is very different from 5 and far more complex and satisfying
And, yes, I did play some 5, as I wasted 50+ bucks on it at release, so figured I ought to play it some, but long ago retired that game. Sad Sad
Newbie question thread is probably not the best place to read up on IV, but rather just use as a tool if you do have a quick question about something.
Best place to start reading is in the Strategy & Tips ->>Strategy Articles sub-forum, as well as the Strategy & Tips forum itself, which you can peruse around and get familiar with. Join in the fun of the Noble's Club game...folks will help you with your game. In particular, Sisiutil's Begginer's guide is a good place to start for the very basic stuff...it is not perfect, but does do a good job getting one acclimated.
Play BTS, of course, and get the BUG/BULL and/or BAT mods. Tool around with the game for a bit to just get a feel for things, then post a shadow/learner game over in Strategy & Tips to get a really focused learning experience - really the best way to learn
Your knowledge/experience with V will have little to no impact are your success with IV
Some key differences though:
1) In V, Happiness was used a very simplistic global modifier to prevent expansion. In IV, the main driver is maintenance costs, which has various factors. Happiness is important in cities, but there are quite a few ways to manage it.
2) V is 1 unit per tile. IV allows for stacking units. 1UPT was viewed by many as a failure of V, but that is subjective, of course, as many V fans do like it. Stacking though makes troop movement far less tedious while also getting benefits of stack defense - for and against.
3) In IV, troops don't magically swim across oceans. You gotta load them in a ship.
4) V has Social Policies. IV has Civics. Social Policies are opened by Eras. Civics are opened by Technologies, and in some cases certain wonders give access to Civics. SPs were interesting. Civics though are more dynamic in my opinion as you are not stuck with them. You can use them situationally, switch back and forth as needed. Incurs anarchy if you don't have the Spiritual Trait or Golden age, but allows for unique and interesting strategies. In other words, in V you basically choose a path almost from the start, while with Civ you have more options to change things up as the game progresses, and as needed.
5) V has uniques for each civilization. IV has uniques for each civilization and their leader(s) [emphasis on the 's' there]. Each leader has 2 traits that give certain bonuses to your game, some being more powerful than others. Each civ has a unique unit and unique building, different combination of starting techs.
6) Big one is Diplomacy. In IV, Diplomacy is more transparent and logical. It has a wide variety of factors that an experienced player has more capabilities of controlling, one way or another. Diplomacy was probably the #1 thing I disliked most about V. It is just plain wonkers.
7) While a late game Civic does allow for rush-buying with gold, that mechanic is not a big factor in IV. Instead, you have the most powerful civic in the game - Slavery - which is something you have access to very early.
8) You can circumnavigate the world on most standard maps and get a bonus for it.
9) Some similarities with respect to specialists and great people, but you have excess to them earlier in IV. In IV, GPs don't create tile improvements. You can settle them in cities for bonues. Most use them for bulbing or special actions
10) V has some interesting religion stuff. IV religion stuff is nice to, but works different in many ways. There are some parallels there though
11) No cities states.
12) Barbarians have a bigger impact in IV..they can take your cities and really destroy your game if you don't know how to handle them. They also generate their own cities, which you can capture. On the other hand, barb ships are just as annoying in IV as in V ..ha