I've been giving a lot of thought to wandering monsters in recent months.
I always appreciated the Wandering Damage Table. It gets the fuss out of wandering monsters
And in a game like GURPS Dungeon Fantasy, where PCs are highly effective at their niche, they're not always much of a threat. This is doubly true in a game like DF Felltower, where I have 9-10 PCs at the table many times. If even half of them are front-line fighters (not unusual), any monster in a group small enough to "wander" generally is just a speedbump.
Don't get me wrong, monsters like puddings and oozes can really be an issue - and we've had a wandering monster utterly maul a PC or two and change the whole shape of a delve. But honestly, the PCs don't change their behavior based on this. They don't use Silence to avoid wandering monsters. They don't move quietly to avoid wandering monsters. They do it to avoid larger, more threatening dangers.
What I've started to incorporate is events. I managed to do so with good effect in the jungles and urban areas of The Lost City
I'm adapting that approach for Felltower, so it's not just "monster" or "fine."
A "Wandering Monster" roll becomes a periodic check for something unplanned by the GM to happen. This can be:
- a monster
- an obstacle (tree down, collapsed,
- a nuisance effect (smoke, bugs, water or other liquids on the path/floor, garbage)
- unexpected alertness on the behalf of nearby critters
- a new trap.
- Wandering Damage of some kind.
Or something of that sort.
We'll see how that effects adventures over the long term. It should spice up encounters and may cause the cost of noise, time wasting, and other time costs to effectively rise without always being a fight.