Rule: Don't split stacks smaller than 7 without a good reason.
Comments: The growth of your legions is a function of their strength as well as their number. If you have legions which are too weak to take a recruit or move into a good recruiting position because that location is too dangerous, then you are losing recruits just as surely as if you had not split at all. This frequently happens to four- and five-high legions, which is why you want to minimze the period of time you spend in that state.
Exceptions: In the early stage of two and _occasionally_ three player games, if you are on a safe part of the board, it may make sense to split more aggressively in order to grow quickly. But it is easy to overdo this.
Rule: Don't split 4-3 without a good reason.
Comments: Just keeping three centaurs/ogres/lions/trolls together is NOT a good reason, unless the three-high stack has a significant function to perform and has a good chance of surviving to perform it. It is generally much more important to lend that extra safety to your good stack than to worry about what happens to your castoffs.
Exceptions: When the main stack is not so hot either. For example splitting off three ogres from three ogres, two trolls, and two rangers. The safety of the main stack is not a big concern, so if the other indicators are right (good access to hills/towers, plenty of rangers left) you might do this. You might even split three ogres and a ranger. And, when you are trying to grow quickly on an isolated part of the board. It's also frequently tempting to split off three cyclops, because those have a much better chance of prospering on their own, and are frequently less vulnerable because they can sit in good defenisive terrain. But you still have to look carefully and not do this too casually.
Rule: Don't split and recruit "deceptively."
Comments: If you are playing against good players, they know where your lords are. And once you enter into a battle with one of them, or summon your angel, they know where your titan is. They are going to know regardless of whether you make an inferior split at some point in order to try to fool them. And at that point all that happens is that your titan ends up with its location known and in a weaker stack.
Exceptions: Occasionally you are in a situation where you dominate the board but your opponents' titan stack is much bigger than yours and your opponent has titan teleportation. In that case you might split just in order so that your opponent doesn't know where your titan is. You can even split three ways, and then when the pieces get up to four split them again. Of course this only applies once you know that fighting with your titan stack means that you have already lost.
Rule: Don't recruit a third tower creature into your starting legions, if you have a choice.
Comments: For long-term recruiting, the third tower creature can be slightly better than the lion or troll in a favorable position on an open board. However, the board is not open, and once again a primary consideration is the strength of your legion, which is what allows it to recruit just as much as the set of creatures that is in it. The lion or troll makes you stronger both immediately (because it fights better than a tower creature) and in a few turns (when the difference is between a _ranger_ and that third tower creature). The third tower creature also generally leads to more awkward splits.
Exceptions: None, really. Maybe certain situations on a crowded board where you can see that you are going to have hills/woods shots but be blocked from directions that would lead to lions or trolls.
Rule: Specialize in recruiting, emphasizing what you have.
Comments: If you have behemoths, don't worry about getting the third lion and looking for griffons. If you have wyverns, don't worry about getting into the center and looking for warbears. If you have warbears, don't worry about getting a third troll and looking for wyverns. If you have griffons, don't worry about getting the third cyclops and looking for behemoths. In all of these cases you are generally better off taking the short term payoff (rangers/gorgons), and then abandoning the secondary line and concentrating on what you are doing best in. If you do end up with both wyverns and warbears, consider picking the one which looks more promising, and splitting the other off early enough that it has a good chance to do something.
Exceptions: None, really. If you can pull off the serpent-hydra stack it is certainly neat, and I have seen it done. But that player still lost. No recipe guarantees success, so pick a plan that has reasonable probability and then pursue it as fast as you can. All of the recruiting lines are viable ways to win; you should not get so set on a certain goal that you disregard the fact that you are doing much better in another direction.
Rule: Don't recruit down without a good reason.
Comments: If there are no more rangers, that is likely a good sign that rangers are already getting close to obsolete. It is certainly a sign that lions are lunch. Recruiting lions with your rangers just in order to recruit something is just feeding points to your enemies. Unless the stack can actually accomplish something, there is no point in making it bigger.
Exceptions: If your ranger stack is six high, and the rangers run out. If your ranger stack is only four high when the rangers run out, you need to give serious thought to the position and what if anything you might be able to kill, and what might be able to kill you.
Rule: Don't split legions which can't improve.
Comments: If you have a legion which has maxed out its growth (e.g., full of rangers), its purpose in life is to attack something. It may be tempting to split it into pieces, even 4-3, hoping you will get two legions of the same strength. But even if that works, those two legions will be much less useful because all of the other legions on the board will be much stronger by that time. And it may not work either because one of your splits might die, or because the units you are trying to recruit run out.
Exceptions: If everything you could possibly attack or which could attack you is far away, and if the stockpile of recruits is not anywhere near to being exhausted.
Rule: Don't split legions which won't improve.
Comments: The main purpose of splitting legions is to get stronger characters that you cannot get if you stay seven high. Not just to get more creatures, to get stronger ones. If you are in a location where no roll allows you to recruit a stronger creature, you may want to stay seven high until you get to a location from which you have more good rolls.
Exceptions: If you are in a safe location, but want to recruit in a dangerous location (such as the center ring), you might want to split and try to become exactly six high, before moving into recruiting position. Rather than splitting leaving yourself five high, and then being very exposed when you don't get the roll you wanted.
Rule: Don't split warlocks off from your titan until they are obsolete or when necessary.
Comments: The advantage of having a warlock in your titan stack (or, even better, _two_ warlocks), aside from the opportunity to kill people who get out of line, is the added safety of being able to recruit in peace. A warlock is worth more than two tower creatures, so your five or six high titan stack is a lot safer from your opponents seven high stacks, thus you are signicantly more able to move where you want and get the recruits you want.
Exceptions: If your opponents can't keep track of what is in your stacks anyway, then the deterrent effect works less well. On the other hand the warlock still helps you survive when they stupidly do attack you. You still might want to accidentally drop your warlock face up on the board while moving, though. The main exception is when you simply don't have room to keep the recruiters you need, for example, titan, warlock, three cyclops, two rangers. This can be especially annoying if you have two warlocks. Generally, though, if you have warlocks you should emphasize paths which won't make splitting so inconvenient. But of course you don't always have a choice.
Rule: Summon angels into your titan stack when possible. Don't split or summon angels out of your titan stack except when necessary.
Comments: The same reasoning as for warlocks, except even more so. Angels in your titan stack make it much safer and much more able to recruit. Or to kill people who are stupid enough or unlucky enough to get in your way. Or just able to survive until your superior skill wins out.
Exceptions: There is one major exception, which is in fact another big advantage of having angels in your titan stack. You can sometimes recruit when you are already seven high, by moving into favorable terrain, attacking elsewhere on the board, summoning your angel out, and replacing it with the recruit. This is not only worth summoning the angel out of your titan stack, sometimes it is even worth fighting a losing battle. The only other exceptions are when the angel becomes the weakest character (you should be so lucky) or when you have lost all of your other angels and want to get an angel into another stack so you can then summon it back in. Finding a way to summon it out instead of putting it in a split-off which might die is better, though, if you can arrange it.
Rule: Don't make an attack if it would leave you with only one strong stack.
Comments: This is the main reason that it is wrong to launch 5 on 5 or 6 on 6 attacks early in the (more than two player) game. Sure, you can often win, with the attacking advantage, but if you are left with only one viable stack you are in trouble. There are all sorts of ways that having only one decent stack can hurt you, the most obvious being that if you lose all your little ones your movement options disappear.
Exceptions: Occasionally when your titan stack is much stronger than anything else on the board, and your other stacks are really outgunned, you want to cut down the points that (one of) your opponents will get, by just losing your other stacks, preferably for half points. Also occasionally, you can cripple your opponent's titan with your non-titan stack, leaving your titan stack the strongest on the board and able to win the game whenever you roll a six.
Rule: Don't fight if you can't win.
Comments: This is obviously an exaggeration, but it is pretty close to the truth. Don't fight and give your opponent full points, just because you want to make the opponent pay for attacking you, or something. Your opponent will be laughing all the way to the bank.
Exceptions: Obviously, giving full points is justified when you have a good reason for fighting (i.e., that the damage you can expect to do to that stack at that time will have a significant adverse effect on the other player's position, or a significant positive effect on yours). But inexperienced players tend to overestimate the fraction of the time that this applies.