It seems everybody noticed that, one way or another, the menace-type mobs tend to level the otherwise uneven playing field.
By all means, using the previous examples, let's call the uneven situation a "Capitalism" (some are weak and poor, others are powerful and have all the best toys).
We can say this is a starting point. Now the game begins, our little game inside a game.
The trick is to introduce some "Communism" into this solemn world of well-established hierarchy.
Imagine a landscape, far far away from the quarantine areas and main trade routes, with Something Good in the center. You'd have to fight to get it. But here's the trouble, what's plain impossible even for medium levels (not to speak total newbies) is a walk in the park for the ubers. This, however, means 2 things, both deadly for a game in a long run: Boring and Unfair.
Therefore, we'll surround the Something Good in the center with a collar of Menacing.
Feeling like uber? Invincible in your uber gear, with all your skills? Well, go ahead then, try to ignore the Menacing mobs, run past em and go directly for the main prize.
Oops!? What just happened? I can see the flashing lights of revival!!??The whole idea of the landscape design, positioning the mob spawns, (trap) triggers, radiation, (after)effects of the Menacing mobs, etc etc - should be to make the frontal assault and brutal firepower impossible.
A new playing field, with slightly altered rules. Have to slow down, do some scouting, figure out the right tactic. Stupidity and arrogance is not awarded. Instead, the clever guy gets an advantage and wins the fight. Or at least improves his chances considerably.
Because, inside there could also be a PvP area.
It could be anything. A mob with good loot, some mining resource, a Capture of the Flag type item, PvP area, or any combination of the above.
The result hopefully would be at least "Not Boring"... which is actually just another word for "Fun!"
