Spurred by a long comment by one of my players on my first after-action report, I've come to realize that there are a few specific things I can do better both for my enjoyment and for the enjoyment of my players.
As I said before, I'm interested at least on some level in what I'll call "tactical play"; that is, in making combat and the exploration of the dungeon that interfaces with it into a realm of interesting, relevant choices.
There are a few prerequisites for this to work. The first is that communication of the tactical reality is clear. Decisions made without input aren't decisions; decisions made on faulty input aren't meaningful.
This is in fact one of the great boons to using monsters straight out of the monster manual, and also potentially one of the great sticking points for a conversion. It's obvious to anyone who has played D&D for more than one session that goblins are less dangerous than gnolls, and bugbears trump both. You don't mess with a dragon unless you brought serious firepower. Medusae are a sticky business. And so on. So, one of the goals of my conversion should be (and is, to a large extent) to preserve at least the relative threat-level these monsters present. When PCs meet an ogre, they should expect a tougher time than they had with the three kobolds in the last room. (Especially with large NPCs in GURPS, this is difficult but not impossible.)
Let's take an example where this broke down: the frogs outside the Moathouse.
Giant frogs aren't immediately evident as big nasty creatures. The mere fact that they're simply dire versions of animals tends to put them on a lower rung than, say, evil humanoids or the undead. Without other input, their threat assessment is inferior. However, that's clearly not the case. So, what could I have done, as a GM, to properly establish that this encounter was meant to be dangerous?
First, let's talk about what I did do. I made it very clear, several times before our first session, that without smart play this could very well turn out to be a high-mortality game. Also, I helped with character creation as much as I could in the communal format we used, and tried to make it clear that there was a vast difference in combat performance between roles specialized for it (like the Knight or Barbarian) and those not (like, say, the Scout).
...but that's it.
I gave them no useful information about this specific encounter, save that a) they're giant, dog-sized and larger frogs, and b) they're ravenous and will attack without quarter. (I believe I very clearly quoted from the book there, because it amused me.) So, quite naturally, my players assumed this might be a bit sticky, but that they would probably walk over it with only some little difficulty.
Those of you who know T1 know that's not true. The book is very clear - this is throwing the characters in at the deep end. So what could I have done, proactively, to make that clear, especially to players new to tactical play?
First, there should have been more environmental clues. Bones near the pool, divots in the road, or generally something to indicate that they are now in dangerous territory.
Second, I can and should specifically call for rolls vs. the appropriate monster-recognition skills, Naturalist, in this case, and then given the PC(s) with those skills the rundown on these monsters. "Oh, these particular frogs have the dark-blue spotted backs of the Greater Voracious Lump-Backs - very dangerous, even to a patrol of armed men, especially in large numbers!" (Or whatever.)
Third, if in my judgment the encounter is liable to go completely foul without some crucial bit of knowledge, I should just straight-up give it to the players. "Guys, these frogs do 1d+1 cr with their tongues some can swallow SM+0 creatures. Also, there are six of them." Realism be damned if it leads to a bad night. (Note: I don't think we had a bad night. Actually, it seems like everyone had fun, even if the Scout's player is a little disappointed in his character's already-imminent death.)
None of this is the same as coddling the players or playing in easy-mode. In no case would I give away information that would reduce the necessity of my players to make decisions as to how to achieve their goals. Also, if surprise is an essential element of the encounter, so be it - you wouldn't know that bugbear is hiding in the rafters because you didn't look hard enough and he's sneaky, sorry. However, when that bugbear makes himself evident, unless bugbears are meant to be some strange exotic creature people have never heard of, the players should know - even if I have to straight-up tell them - that bugbears are almost as strong as ogres and are smart enough to use guerilla tactics.