I mentioned during the summary yesterday that I need to deal with some problematic Gate spells in DF, while still allowing for Gate spells in DF. Please note I'm using GURPS Magic plus Wizardry Refined, so not all of the spells are available.
The Gate spells as written in GURPS Magic are good for a more normal game. If you have far-flung gates or the game is centered on them, the spells work generally fine.
In a megadungeon, spells like Seek Gate are just asking for abuse as exploration substitutes. Just keep casting Seek Gate to map them out, triangulating as you move around. To some degree that's just smart play, but again, it changes the game from "boldly stride down the corridor seeking danger" to "use this spell until you've determined if you really need to adventure down that corridor or not." I can see an hour of playing time whizz by as people cast Scry Gate, move a few yards, cast it again, use Cartography to fix the map to reflect the detected destination, etc. All the while I'm counting squares on the map and checking if there is magical interference or closer gates I'm forgetting. Aargh. That turns "mysterious ways to find new adventure" into "beacons for pre-mapping."
The only bit I like about it is finding the way back if a gate is one-way. "We're here, and my magic tells me the way out is there." That's cool, I need to keep that.
Other spells need tweaking, too. Scry Gate has this bizarre "smells" aspect to it. It reveals the smells behind the gate? Obviously the Great Wizard Farnsworth created it. My players instantly realized that if smells come through, clearly the particulate matter that creates the smell comes through, so Scry Gate pulls poison gas through gates. If it doesn't, and just tells you the small magically, it's just weird that it isn't caster-only.
What I'm thinking at the moment is:
Scry Gate - as written, but without the smells aspect. Sights, possibly sounds. I kind of like a silent movie effect of viewing it.
Seek Gate - I like the "find the way back" aspect, but not much else. Perhaps only a specifically known gate, or a gate to a specific location, can be sought. So "Where is the gate to Felltower from here?" works, or "I want to try and seek a gate to Hell" might work, with the penalties listed (-2 for closed, -5 for an arrival point for a one-way) but not the -10 for specific destination as that would be a requirement. If you get lost you can triangulate by seeking around a known gate, which is annoying. Maybe adding Once Per Day will fix that, too. I could do both or either.
Control Gate - probably just forcing them open or closed, none of this dragging them around stuff.
Analyze Magic - will tell you the type of gate (same world, plane, time, etc.) and possibly a hint at where. Critical success will reveal lots of details. So success might be "This is a gate to different world!" and a critical success might be "By which I mean, it's a gate to Hell." One Try. This plus Scry Gate can tell you a lot about a destination.
Mage Sight - an active casting of this spell will detect closed gates. The spell needs to do more anyway.
And related only because it's a prereq, I do need to make Seek Magic more useful. Or ditch it and add a different prereq. It's expensive, bound to be stacked with penalties ("Okay, I spend 6 base energy, and excluding these five magic weapons, seven suits of magical armor, my wand, our potions, that scroll, and my magic hat, I seek the nearest magic item. I rolled a 10." "You find Hjalmarr's magic ring." "Dammit!")
And obviously, gates won't work on constructs of pure magic like Wizard Eye. Crteated Servants clearly work, which I already regret, but I let it work a while back before I'd considered how annoying that would be. It won't work on all gates, though, since I have some different types out there. At least they're terrible, terrible scouts (IQ 9, Per 9, rarely any skill), and serve to alert people on the arriving end that something is coming.
Lots to fine-tune here. But mages should be able to affect gates to a degree, without either the breadth of power implied in GURPS Magic or lack the abilities whatsoever. I need to tune the spells to the world for this game, not the other way around.