-The number of horses shown in a tile is the same (up to a point. 4?) as the number you receive as a strategic resource. I don't know how long this has been true..
I now pay greater attention to what is happening in the game and focus more on my chosen strategy.
It always bugged me that uninjured AI units seemed (by that different icon shape) to be able to fortify, whereas only my injured units seemed to be able to do so. Then I discovered that "alert" lets an uninjured unit fortify.
I just recently noticed the horse thing too. I just thought they were alternate graphics for variety's sake and then I noticed that they correlated to the number of the resource.
I had played 2 games, and in both had long rivers to plant cities on, and in both got too around the middle ages and was having severe money and happiness problems, gave up and went to a third game, only a small river so I had to connect with roads and suddenly that symbol that I thought meant I had discovered the periodic charts appeared and the whole game I was pretty much flush with cash and was able to afford happiness structures. I have been playing Civ 4 so long just never thought to look and see what that symbol meant.
I don't understand why rivers don't allow trade routes anymore. You used to get a trade route if two cities were on the same river or a road/roads ran from that river to cities.
I think watching some of the Let's Play videos has been helpful to find out more about what I didn't know. Bibor and Mad Djinn have illuminated me on several things, in particular AI behavior, how certain strategies work together, and timing issues. I now pay greater attention to what is happening in the game and focus more on my chosen strategy.
They removed culture bomb border expansion ): I figured this out while doing the one city challenge.
Historical Info:
A pikeman is a better-trained and armored spearman armed with a longer, sharper weapon. Unlike the shorter and lighter spear, a pike is almost always used two-handed. Historically pikemen were most effective against other infantry and cavalry, but as they lacked shields, they were quite vulnerable to archers.
Specialists produce A LOT of unhappiness - noticed this when I went conquering and moved into -20+ unhapiness. 10+ unhapiness was produced by scientist specialists.