To survive against the dangers of the dungeon, do research and ready some commonly available (and not so commonly available) combat options for creatures that you're likely to encounter.
In haunted tombs, for example, holy water, magical weapons, and the like are pretty much standard. If you can't afford the full-on magical sword, spend on a dagger or smaller backup weapon. Daggers are great because the mage can use 'em if all other party members have dropped.
Here's a quick checklist for weaknesses and banes:
- Holy symbol -- only if the GM is feeling generous
- Holy water -- does damage to most undead
- Silvered weapons -- affects various undead and the werecreatures as well
- Magic weapons (primary if possible, check the pluses) -- always good to have anyway
- Fire -- great with webs, cubes, spores, and - in conjunction with oil - folks in the other room whose only door you've spiked shut
- Electricity -- good stuff for metallic things or things in water
- Slings -- useful for distanced bane use
- Water -- not always that useful, but you have some already anyway, right? Find out if it'll save your life against something, especially in conjunction with electricity
- Herbs and Vegetables -- they say wolfsbane helps, and garlic, and seeds (your GM mileage may vary) but there's no sense in carrying this stuff unless you know you're gonna need it
Case in point...
Arduin, Wraiths, and Coins
True story. In one of the Arduin dungeons, we encountered a wraith. We were a party of six, but let me read to you the description of the Common Wraith in Arduin:
Only weaponry of silver of magik may harm them, silver doing but half damage...They cannot be mesmerized or mentally controlled, but the priestly Glory Glow will bum them at the rate of 4 HP each melee round they are inside it. These beings, because they are non-corporeal, can drift through solid walls with no difficulty or reduction in speed.
Well, being a relatively low-level party we didn't have a single magic weapon to our name. Silver weapons? Nope.
So when we encountered this nasty thing in a room, only magical spells had effect and that resulted in our mage being targeted and using up his valuable memorized combat spells! So what to do?
We realized that we did have silver weapons: our silver coins, in the purses tied to our belts. So we had a thief with a sling hurl his coins at range while the rest of us descended upon it like mad hooligans, swinging our coinpurses through it (the pouches went through it, but the coins did not) until we beat it back into the afterlife.
Most of us survived, as opposed to none of us.
Moral of the story: never underestimate your more mundane gear. A bane is a bane is a bane.