Baldur's Gate 3 players will remember this quest where you have to blow up a rock to free some people trapped behind it.
The intended solution is, of course, explosives. The Force damage dealt by smokepowder is one of the few things that can damage the rock at all. It's immune to most damage types, and thanks to its "Medium Toughness" condition, only big damage can get through.
Now, if you don't feel like using the convenient explosive option, there are some alternatives. Bludgeoning damage works, if you've got a character with Great Weapon Master and a big hammer. Thunder damage can get through as well, if you roll high with a Chromatic Orb. That's about it though, it's immune to every other... wait... why does it only resist Piercing??
It baffles me that they didn't just make it immune to Piercing. It might as well be! With resistance, you would have to deal at least 44 Piercing damage in one hit to get through the threshold! Impossible.
Or is it?
This is the infamous Titanstring Bow. It's a +1 longbow which adds the wielder's Strength modifier as bonus damage. Using an Elixir of Cloud Giant Strength sets that Strength modifier to +8. With a maximum Dexterity of +5, that's 1d8+14 Piercing damage. Add in the Sharpshooter feat for another 10, and we're at 1d8+24. Impressive, but not enough.
Unfortunately, many of the best damage riders cannot be used on objects. Hunter's Mark, Sneak Attack, and Manoeuvres are out. Flourishes do work on objects (for some reason), so we'll make Wyll a College of Swords Bard and get an extra d8 of damage. The Enlarge spell adds a d4, and a 4th-level Magic Weapon cast by War Cleric Shadowheart gives us +2. New total, 2d8+1d4+26 Piercing damage.
A really high roll could put us over the edge, but let's try and squeeze out as much as we can. Bracers of Archery for +2. Diluted Oil of Sharpness for +1 (stacks with Magic Weapon). And finally, the Diadem of Arcane Synergy to add Wyll's Charisma modifier, which I was able to boost up to +6 with the secret shrine in Act 2. All in all, this build can do 2d8+1d4+35 Piercing damage in one titanic hit.
And two of those got the job done!
If you're curious, here are some other methods to add damage that I tested:
Valor Bard's Combat Inspiration, War Cleric's Divine Strike, Hexblade's Curse - can't target objects
