This is the fourth installment in my Checking Out Chainmail series. The other installments are here: Introduction, Part 1, Part 2, and Part 3.
The next section of the rules deals with terrain, beginning with descriptions of the effects of different types of terrain and ending with a section on choosing specific terrain for the battlefield. There are rules given for the following terrain types: hill, wooded, marshy, rough, ditch and rampart, river and stream. All of the terrain types slow movement by 50% except rough and river and stream. All terrain prevents charge moves. Most also have other special rules or effects on particular troops. Most of these are fairly standard adjustments.
Rivers, though, are slightly different. For rivers and streams: "Treat individually as to fordability, penalty for crossing, and so on. (A typical stream would require 6" to cross and prevent charge moves, while a typical river would require troops to halt before and after crossing and cost an entire move to cross.)" (p. 10) This kind of variability and need for planning between opponents is a reminder of when these rules were written and the breadth of their applicability. In rules sets developed more recently, the normal tactic would be to describe the effects of streams and rivers in more detail or simply write them off as impassible except at particular points like bridges and fords. The variability in regards to rivers also highlights that these rules were written by and for gamers who like to house rule and modify their games. Just like the options in the turn sequences, this is a reminder that none of the rules is set in stone. They should be modified to best simulate the kind of play the group wants or that the battle situation warrants.
In regards to choosing terrain, the rules present a system where different terrain types are listed on 3x5 cards. The players take it in turns to draw and place terrain on the table. It's a nice, elegant system that I am probably going to adopt for all my wargames from now on. It's also a great example of the kind of subsystems that are so typical of the classic wargames and roleplaying games.