Keeping track of what the BBEG is doing

[Nettlekid]

As a DM, I think it's pretty easy to see the BBEG as a challenge for the players to overcome. They may be great and powerful and Machiavellian, but in the end they're more or less expected to fall and for the heroes to be victorious. Sure, this won't ALWAYS happen, but it's the standard.

A BBEG is often thought of as either one step ahead of the party if they're both heading toward a common goal, or ready to preempt the party's actions if the BBEG is some tyrant to be overthrown. In either case, what the BBEG has done between the last encounter and this one isn't really as important as whatever they're doing right now. Imagine like, the Legend of Zelda games. Link almost always stumbles upon the bad guy or a lackey right as they're taking a special secret sealed-away treasure, or vice versa. It doesn't really matter how the bad guy knew this is where the treasure was (while you had to go on all those quests to get the village elders to tell you) or how they got through the temple while leaving all the puzzles unsolved for you.

So what if you want/need to keep track of what the BBEG is doing? For example, let's say you have a player who can't make regular meetings and for interest's sake they switch to the evil team to have a parallel storyline instead? You'd need to know what the BBEG is doing, why they're going after whatever they're going for at this moment, where their info is coming from, that kind of thing. How would it be best to keep track of the BBEG's agenda in a plausible way, without it feeling too mundane or losing the stylish mystique of the BBEG?

[NoACWarrior]

well depending on how your run your BBEG, you could have the evil PC do a couple of things
a) harass the other PCs
b) cause mayham as nessesary, only to be framed and used as a scapegoat
c) longer gopher quests (get me suchnsuch item from thattherecave)
d) integrate the evil PC as an army commander training troops and leading a strike team on tangible missions
e) being the BBEG's protege who follows him around and does things as BBEG does, including evil contemplation and evil meditation, this also requires working on an evil laugh and making evil plans (a whole lot of RP and disturbed RL neighbors).

[VoxRationis]

A lot of villains don't tell their minions everything, both for security reasons and so they can have someone to monologue to without having to worry about them wriggling free of the ropes and escaping midway through the speech.
Basically, you know (or should know) the general plan of your arch-villain. Since you know that plan, you can come up with some steps they need to fulfill that plan. If you're worried about it being too simple with both the arch-villain and a PC working on it, you can invent some impediments of various natures, maybe even a few underling revolts or something, to slow it down. Make it clear that the villain, for all his resources, still has to contend with the same sorts of hassles the PCs do, and can't rely on the loyalty and competence of all his "teammates" in the same way a party can. Have the villain run multiple plans simultaneously (trying to rule the world tends to make more than one person at a time mad at you), or have to take steps back to prevent others from rebelling/counterattacking.