Is that thing going to kill you and your group ?

The most important thing to look for - in the standard, not “simplified” interface - is the number of arrows.    Strangely, level is a secondary consideration.

No arrow = an average opponent.
^ is a strong opponent.
^^ is a very strong opponent.
^^^ is a group-only mob, very tough.
Epic x2 is a raid mob, 2 groups needed at its level.
Epic x3 and x4 are for raids, 3 or 4 groups needed.
One down = An easy opponent.
Two down = Very easy opponent.
Three down = The easiest possible.

Consistently, whatever the levels are, the arrows give me more information about how tough the mob is to kill, as in how many hit points it has, and how tough its armor might be.     This is not to say ignore level, instead to realize that it is secondary.

Level considerations are much easier.     You should be able to kill something that is your level.      It’s easier to simple depending on how many levels you are above the creature, and harder to impossible depending on how many below.

Grey - No challenge.
Green - You can solo this when barely trying.
Blue - You can solo this.
White - You can solo this; but pay attention.
Yellow - You might solo this; but you might die.
Orange - This is a duo or group mob.
Red - This will kill you.

So how to deal with the contradictory indicators that are present here ?     Depends if you’re soloing or if you’re grouping.     Grouping is complex because of the many possible level ranges.    Solo is a bit easier.

If it’s a Red mob, with three down arrows, you still probably don’t want to try it.     Otherwise the hardest one to attempt is :

Orange - Three down.
Yellow - One down.
White - Even.
Blue - Even.
Green - ^.

Now, suppose there are multiple mobs you are soloing?    Now the arrows start to have an easy conversion factor.     Add an arrow for each additional mob and consult the chart above; so for example a group of three triple-down green mobs should be doable solo.

Now we’ve got everything but greys figured out.    Greys are a special case; they are “no challenge”, but can be everything from epic to triple-down.      Basically, if it’s grey don’t give a second thought to any number of opponents ^ or less.     The number of arrows gives you an idea how *long* the fight will be, but its outcome should be no question.

A grey ^^ might give you trouble.     Go after this if it’s 12 levels lower than you (grey begins at 11 levels).    A grey ^^^ can be very deadly still; wait until they are 13-15 levels lower than you; 13 at lower levels such as 25, or 15 at higher levels such as 45.

For the ^^^’s, this is also very dependent on the type of mob and your class.    As a mystic, I put out low DPS and therefore am ill equipped to handle a ^^^ healer even if grey.     I have to wait until he is so grey that he can’t even put a hit on me any longer.      Once I reach that point, my DPS isn’t that important, I can just chip away at him until he goes down.

An epic grey is something I want to solo someday, but I’ve yet to figure out the safe level to do it.     Not that I’ve ever tried either; most epics are level 20+.   20 levels higher is probably safe for an Epic x2.     Perhaps 25 for Epic x3.

Time to try soloing the Windstalker Rumbler and see what happens; I never did do that quest either.      At 45, my mystic is 25 levels above it so that would be a good test.

For groups, it depends on how many people you have, their classes as in class balance, and their levels.      Rarely is any number of blue or green mobs, not ^^^, a problem.     A full group with an average white-con level can kill a ^^^.      Sometimes even a green ^^^ can be defeated by a duo; often a trio.     The way to tell if you can survive is to rely on your solo experience, and always start with easy mobs and work your way up.

The Everquest2 con system is rich, detailed, provides a ton of information, and is as complicated as all get out.     Hopefully this guide demystifies it a bit.    Now some classes can solo better than others, so you’d need to revise my estimates, but I’m pretty sure this is a good baseline where it’s safe no matter what your class is.