Caves: Monster AI and Layout Analysis - by Cyrene

Ok, I almost always play rogues, and have always hated caves. Period. No narrow hallways, no good doorways, lots of open space, lots of nasty monsters. I would rather play hell on any diff than caves. Still, hell/caves is where the exp is, and I have been on a power gaming trip lately working on my 5@50 squad. Also, my CAT loves to hunt pw in caves. After a zillion hours of play in caves, then, I started to (belatedly) notice a few things. This post will concern itself with part 1 of monster ai, caves optical allusions, and a special attitude adjustment head-banger.

Monster AI
Two frequent hell monsters are dog types and storm types. Both sport dual attacks: ranged magic and up-close melee, both of which can be quite devastating. Note, however, that their ai provides a 1-2 square buffer where they shift attack modes and do nothing at all but rush you, trying to transition from ranged to melee attack. If you can find a way to stick them in that range, they do nothing but mill around. Exhibit A:

Note the absence of spit. And they are too dumb to open doors. These pooches are pretty much screwed. Occasionally, one will drop back a 3rd square and lob some spit. This is annoying, but much better than taking on a quick attack through the gate while others spit at you. Lets look at another example.

Here I came around this corner, and found a pack of 5-6 spitters. Instead of falling back, I opened the highlighted door and rushed down the narrow corral. Now I have six dogs milling around with no offense. Does anyone else predict firewall practice?

Something else about this layout caught my eye. As this is dlvl 10, and the Poison Spitters mean my good old buddy PW is around, I decided to combine missions and exploit this optical illusion to kill PW for the borement of the masses 8-).

I went and found and fetched PW and his jolly crew of expectoraters to almost the same spot. Then I dropped my armor to prove a point. You see the dog in front of me is doing nothing, not moving, not spitting. PW is the bright square just behind doggy a. Why don’t they attack? Look closely one rank north/12 o’clock. See the half of a fence section? Well, there are no half sections in Diablo. That is a logical solid wall. The fence actually starts at the post. The dog is in the square with the pseudo-fence/rock, I am one square south. It cannot see me, Yet, for me, the game lets me see him. Poor doggie. Here’s another shot that I lit up to illustrate the point.

Casting directly in front of me, the FW on the back row lights PW up (thanks Charis and KoP for showing me how to cast this). I skip a row with the visible dog in it, then cast another on the next row closer to me to show how the game is treating that half fence square. Solid, eh?

This is one way to wipe out PW and his pack in Hell/Hell with no armor and no physical weapons….

That covers caves monster ai and optical illusions part one.

The picture on the right illustrates just that...a hole in the wall that I can walk through and shoot through but the monsters do not see. Note the targeted Obsidian Lord is walking *away* from me. Hehehe

This is a lousy screenshot to explain why, though, due to the angle. A better example is the pic below. Note that the dogs in PW's pack are in range, yet the spits are being blocked by the virtual wall. OTOH, I can see and shoot through it perfectly, as you can tell by the bodies and gold on the ground.

The effect is caused (this is all theory from here on out) by the way the game treats out- croppings in caves. The"point" that I am standing by covers all but one "sub-square" of the "square" I am in. Magical
effects and monster line of sight see the entire square as blocked.
But the player (if he/she is extremely careful to stand just right) is given an open line of sight and projectile path. Note that my left foot is *just* inside the line of the next grid. Depending on how these images translate to your computers, you will also note that I keep my Diablo gamma cranked up high enough so that I can *see* the grid pattern in caves--for now-obvious reasons. (cheesy? yes. OTOH, here I am in an IM solo game, those are the stairs down in the background, and here is PW. Is Diablo playing fair? I think not...)

Still to be tested is the effect of virtual walls on player spell effects. I know it blocks area spells, like FW. I've never tested other spells much, as I usually only use this tactic in IM, and in IM I don't have the spells or mana to play around 8-). I did do a brief test in cats one night (with Simba, iirc, who politely stood by while I flirted with disaster playing with Deathspit's mob testing projectile vs Fireball blocking by a Cats virtual wall). In that case, it seemed
projectiles always got through but Fireballs were *mostly* blocked. It was a bit difficult to test, as virtual wall effects are present in cats and hell, but only slightly. Caves is where they really show up.

Note also that this kind of spot is useless against storm riders, as their AI says "If you know where the hero is but can't reach them directly, mill around and try to find a direct route." Half the pack would move up and attack from the front while the other half of
the pack would circle around and attack from behind (which is exactly
how I died about 30 seconds after this screen shot--