[OOC] Return to the Rusty Rat

[DM Surranó]

The antimagic field covers 10' radius centered around the bottom of the iron wall. Will add it to the cross-section for clarity. If Lugar is to do something magical he'll have to stay clear of the antimagic field (completely I should say) and he can do so by staying close to the walls anywhere except west. Staying close is imperative since his increased space of 10' already means he's standing on an narrow ledge (5'). I put him on one such possible place.
There seems to be no way into the vault other than crossing the field; passing through solid walls somewhere; or descending through the trapdoor from above (which Toot hasn't seen yet from current position but the others explained so that the doodid can imagine)

EDIT: stone shape and a 17 cu ft shaft... The total 45 degree shaft would be about 19ft long but if you make it a bit steeper you can fit into 17 or even 12. The latter means the shaft would be 14.5 x 14.5 inch cross-section (or 16 inch diameter).
According to spelunking rules, this is "crawl-navigable" for anyone below four times these figures (64" = 5'4" means dwarves, gnome and black bear). It is "awkward" for anyone with a shoulder narrower than these figures (Murkatos maybe... though I lean towards him having wider shoulders. He's an expert armorsmith, after all) and "tight squeeze" for the big fellas (Maul and Giant). Our gnomes are unusually short so it's simply "narrow" for a certain "tiny gnome".

Crawl-navigable means you have to crawl proned (5ft per move action unless I'm mistaken) wearing no armor heavier than light and have to drag behind all stuff like backpacks.
Awkward means you can crawl 5ft with a single Escape Artist check (DC 15; repeat for every 5 ft)
Tight squeeze means 5ft with EA DC 30.
So it's not impossible for some but may cause more than a bit of disadvantage if sh*t happens halfway.