Hello! So it's been quite a while since I worked with Hammer. My last map was a personal success but then again, it's been a couple of years. I'm interested in getting back on track, although keeping up with all that I've learned so long ago is still a struggle. But I'll get there.

I'm thinking of creating something big this time. By big I mean the environment being big. The scale and space, the distance between you and the surroundings. The puzzles aren't going to be in the same sense. My worry is that I'll be thinking too big and end up with a map that's not going to compile properly. Would you please remind me if there's a limit to how big a map can possibly be? And how to check on it? I guess there's a limit of entities, textures and such.

The maximum map size is 32,768 units in all directions, though to keep it from leaking, you'd need one-unit walls on each size, effectively making the map 32,764 units cubed. If even that's too small, you could probably cheat with linked_portal_doors if your map is set up right.

Thanks for the answer! What about the number of brushes, different entities etc?

From experience a map can be as large as you want, including assets - however too many entities can cause the map to be physically laggy and crash for some players if not optimised properly.

I would suggest make multiple maps and split it up.

You can find the "limitations" of the map at the end of the black window just after your map has been built in hammer