[2021] I heard you can't really make Underground bases anymore ??

This is a common misconception. You can make an underground base. What’s changed is that zombies can dig now. Specifically, they’ll dig down if you’re below them. They won’t dig under a wall if you’re both on the same level.

What this does is put underground bases on a more level playing field with above ground bases. Before, underground bases rendered the player completely unreachable - in other words, infinitely safe for a nominal effort. That breaks the design goals of the game, e.g. that the Blood Moon horde should be nontrivial for those that choose to play with it on. So they fixed it to where it’s possible for zombies to reach you underground (as well as on stilts, and other base setups the zombies couldn’t handle before).

Now we have an adjustable scale in the settings for how much block damage zombies can do. Instead of a binary where zombies can tear through x but are totally stumped by y, we start with the premise that zombies can get through anything and everything, and the player decides how much time/effort it takes the zombies to do so. To the extent there are other things that stump the AI remaining, I expect them to be remedied in future patches until none remain.

This becomes a heated subject for some, and you may expect this thread to swell with responses that the devs are in an arms race with players, trying to ‘beat’ their strategies one by one until nothing ‘works’ or there’s only one way to play the game. But I dispute this interpretation.

Originally posted by Ming:

Originally posted by Zordrage:
so they wont gonna attack my Door way above me but straight start Digging down totally ignoring everything i build above ?

If they know you are there (and the blood moon horde always does) then they will take the path of least resistance. If that means beating down your door and coming down your ladder to get you. They will. If it means digging through 20 layers of dirt and rock to get you. They will do that instead. Which ever route was deemed the fastest and least effort way to reach you.

Indeed. So one of the mistakes a base designer can make, in my opinion, is to just make everything really strong and hope it's enough to hold. It might work for a while, but it's a risky strategy long term (you can theoretically brute force it, but that'll get mighty hard with demolishers). And I suspect a lot of underground base designers had this mentality. "I'll just put so much dirt and stone between the zombies and me that I can ignore the horde and not have to worry about a base design."

But I digress. My point is, if you're going to do an underground base, or any base really, you should design it with weak points in mind. For instance, maybe that means having a big obvious pit where all the zombies jump in, with you and your traps ready at the bottom. Maybe it means a thick concrete roof to your bunker, but you deliberately don't reinforce one section so that if the zombies do get in from above, you'll know their entry point in advance.

In other words, don't let the zombies choose the path they take. You choose their path through your own design, even if the path of least resistance is so packed that no zombie ever finishes traveling it.

Originally posted by Ratsan:

Originally posted by Crater Creator: This is a common misconception. You can make an underground base. What’s changed is that zombies can dig now. Specifically, they’ll dig down if you’re below them. They won’t dig under a wall if you’re both on the same level.

Actually they do and they will dig under walls even if I am above them. I have seen them go to a nearby POI and start bashing the walls and/or digging under it for no reason I can figure out other then wonkey AI... Being zombies they must have some brain rot so its not an issue for me but it certainly does not track with the statement.

I'm not saying what you saw didn't happen. But in public comments, the AI programmer has specifically identified digging under a wall to get to a player at the same level as something he's been designing the AI to avoid doing. That's the basis for my claim. Is it possible the zombies wound up in a depression that was there before they arrived? It's easy for an errant explosive, bit of cop spit, shovel strike, etc. to remove a block of dirt.