It’s widely acknowledged in the community that our minion AI has serious problems. The most severe problem is when minions stand by and do not enter combat with the Necro.
So let’s try to make some theories, test them, and perhaps we can give AN some good leads.
1. Not Unique. AI problems aren’t unique to Necros. I’ve heard at various points of Thieves having problems with their summons, Mesmers having problems with particular phantasms, etc.
2. Number of (Potential) Minions. Necros who are into minions can have more out than most professions. A Ranger has at most one pet out at a time. Elementalists could have two summons (Elemental and Lesser Elemental), but generally only use one. Thieves could have three summons. Mesmers could obviously have a boatload of illusions and phantasms, etc. Mesmer Illusions and Phantasms work pretty well — though I’ve heard complaints about some Phantasms just standing by sometimes — so the issue is not as simple as having many minions/summons/pets or having the capability of having many, but it could be a contributing factor.
EDIT: I spent the skill points on the Flesh Golem and have found that this single minion has issues. It does appear that melee minions have particular problems, which suggests Pathing issues…
3. LOS/Pathing issues. GW2 has some deep and lingering issues with LOS. This has affected teleport spells, Elementalist Ride the Lightning, etc, and most professions see erroneous Obstructed messages as they operate. Mesmers were recently hit with a huge nerf stick when their illusions/phantasms suddenly required LOS, and suddenly they were facing LOS issues. I believe that LOS issues could also cause or be related to pathing issues, so “LOS” may actually affect non-ranged minions.
EDIT: Based on my experience with the Flesh Golem, it appears that melee minions act a bit strange, even if they are otherwise working correctly. They don’t have particular problems following, but if separated from their target (the Flesh Golem charging through its target and beyond, for example) they can appear “confused”, sometimes as if they can’t figure out how to get to the target and sometimes they almost appear to think they are next to their master and out of combat.
It has been noted that minions may behave well underwater, which would also suggest pathing issues. (My theory being that underwater straight lines tend to work.)
4. Targeting and Entering Combat. I have a sneaking suspicion that target selection, playstyle, and entering combat have something to do with it. That is, when I’m wielding a staff, I can easily drop five Marks and even a well or two, and be in combat for a while without targeting anything. Certainly other professions are capable of opening with AoE or traps or other non-targeted skills, but I don’t really see a playstyle/rotation that is very common among other professions that actually does it.
Perhaps, if you have a target and enter combat by attacking it directly, minions are more likely to know what to do, but if you enter combat without a target perhaps subtle bugs may be triggered resulting in the minion staying out of combat for an extended period of time. This may also be why Mesmers have fewer issues than Necros even though they can have many illusions/phantasms out: they are almost always tied directly to a target that must be targeted when they spawn.
5. Traits. I haven’t voluntarily traited for minions in any way. Could a common minion-oriented trait be causing bugs in some way?
6. Minion Anti-Collision Code. PinCushion observed that it appears that Minions are coded to repel each other so they don’t stand in the same spot or pass through each other. Combined with Pathing (Item #3 above), a Necro with many minions in an area with difficult pathing may end up with minions that are stalemated and block each other from finding paths/LOS to the target.
7. Tab-targeting. Perhaps if you tab-target through nearby mobs, the minion may remember “targets” and run off to attack something you never actually attacked. (At least one person has noticed that this happens and is repeatable.)
8. Summoning while in combat helps. Several people have reported that minions summoned while you’re already in combat seem to act reliably. Which might indicate that there is something about the minion’s transition into combat that causes a problem.
Have you done any experiments or found any workarounds that seem to avoid minion AI issues, particularly minions standing around? Please share. (I think that issues of minions attacking random mobs are secondary to them standing and doing nothing, so would recommend we tackle that first.)