In my recent lab challenge playthrough I reached the top floor with the friendly little turret waiting for me and was going to head back down, but pressed “climb up” instead of “climb down” by mistake and it let me somehow climb through the roof, so I could then easily just jump down and skip the whole lab challenge. I was standing on a downstairs tile next to a wall when I did this.
I did some searching and found a mention of this exploit here as well: https://www.reddit.com/r/cataclysmdda/comments/6lji08/lab_challenge_help/djva9zg/
It seems it might be caused by there not being any floor tiles on the roof level of labs, since I remember there not being any tiles up there compared to some other buildings I’ve climbed.
And roof tiles does not counts as the floor on the upper level either.
I’ve playtested this three month old version and I don’t see this happening even by going up and down the stairs.
Besides, this was only when I added the experimental 3d levels, which the game specifically says dude this fucks shit up and doesn’t even work why is this option even here. In the 2d version it just told me “nope, there’s only a downstair here.”.
So I don’t really see what the whole problem is, unless they reinvented the wheel in the last few months and fucked something up. Even then, 3d z levels is beyond fucked up. Zombies can climb 10 stories buildings and just waltz on your roof to smack your ass in five seconds, because they just don’t care yet and treat that shit like sidewalk.