This guide covers the building of defensive walls and Dino Gates in Ark Survival Evolved. Also included are tips and tricks to help you get your walls and gates installed quickly and easily. The example used is the building of a Dino Pen with a Dino Gate.
It is often easiest to start by placing the gateway and gate. Make sure the outline is facing the direction you want before placing it. That is an expensive part to demolish. I have found that standing where you want the inside to be, and looking out, is the best way to get the gate placed correctly.
Once you have the gateway in place, the gate itself will just snap right into the gateway. That part, at least,doesn't usually cause a problem. These gates are supposed to be usable while mounted. In practice, however, I often find that I must dismount to close the gate after exiting. Opening the gate to come in or go out is usually not a problem.
Another thing to keep in mind is that you may want to install the actual gates into the gateways as your last step. Should you run into problems building the walls, and then need to move that gate, it's expensive enough without having to demolish both parts. I've taken the habit of putting the gates into the gateways only once everything else is done.
Next you'll want to install the fence foundations, and then the walls. Because of the rather unstable placing mechanism at this time, I recommend that you only place one foundation segment at a time. Be very careful to make sure they all line up. I've had them 'snap' into place but in reality they were just a bit off being lined up and that caused a big section of my wall to be out just a little.
The placement of the foundations is fairly smooth and stable. And if you are careful and pay close attention while placing wall segments on the foundations you'll see whether or not they are going to place facing the right direction. If not, just press E and you'll be able to flip the wall segment the right direction. Of course, you must do this before you place the wall or you'll have to demolish the wall and replace it with one that is facing in the right direction.
Because of the way the snap points work, you really need to place fence foundations first - before you place the Behemoth Gateway. This is the only way you can be sure that it will line up with your walls. Otherwise you can end up making quite a mess trying to close off your walls completely.
The corner to close the wall will need to match perfectly. These walls have no smart snapping or shaping. If a segment is out just a hair it may not connect and may refuse to place. You'll want to make sure you keep your corners perfectly square and count out the sides exactly.
There are cases where even if the corners snap together you'll still end up with a small visible gap. This small gap should not be a problem. People shouldn't be able to glitch through a tiny visual gap, nor should wild Dinos be able to glitch through. Keep in mind, the gap I show below is on fence foundations that had snapped together just fine.
Also keep in mind that with the way snap points are setup on the Behemoth Gateway you'll probably end up with your walls passing through a small portion of the gate as shown below. It looks kinda dumb, but the walls passing through like that ensure at least that it is sealed tight and because they don't stick out far enough to block the actual opening it won't be a problem.
Also keep in mind that with clipping issues you should not use natural features as part of your wall. If, for example, you use a rock face as a wall along one side of your base, it is very easy for an intruder to glitch past the rock wall into your base. For an effective wall you must enclose all four sides of your base and make sure that the corners meet up properly. And yes, this is a glitch that should be fixed at some point.