Monster tactics 101?

[Aulirophile]

+11 is standard for Rogues/Thieves at level 2. +5 from Dex (because not starting with 20 Dex if you're a a Dex Primary attack class is a poor decision)+3 Prof (Rapier or Dagger)+1 1/2 level+1 class feature (Rogues with Daggers, Thieves with all Light Blades) is +10. Expertise or a Magic Weapon is +11. Both would be +12, so he isn't even at the maximum that is reasonably possible. Being hyper-accurate is the Rogue shtick, Thieves inherited it. Nowhere near the effective bonus Avengers get, of course, but in the Avenger's case their accuracy is their Striker feature.

 

[Spatula]

Personally I use inherent bonuses so the issue takes care of itself. In any event, PCs shouldn't really expect their first magic armor until 4th-level (if you use the inherent system, that's when they get their equivalent)

Inherent bonuses are deliberately lower than what you would get with normal magic item distribution. According the designers, they set it up that way to make magic items found as treasure still attractive (at least that's what it says in the Dark Sun Campaign book).

I would suggest using lots of controllers or artillery that target defenses other than AC. Note that plenty of other monsters might have an attack that doesn't target AC as well, such as a brute that has a multi-hit "swinging weapon" power that targets Reflex.

This! Defenders usually have ACs that are much higher than their Fort, Reflex, and/or Will. For a knight, Reflex & Will are probably very hittable.

 

[Jhaelen]

Inherent bonuses are deliberately lower than what you would get with normal magic item distribution. According the designers, they set it up that way to make magic items found as treasure still attractive (at least that's what it says in the Dark Sun Campaign book).

Ah, interesting!
I was already wondering about that when I looked at my characters at different levels and had the feeling they had trouble to keep their defenses at reasonable values.

 

[Quickleaf]

Suggestions on building or running more challenging/dangerous encounters?

For my games thru high heroic and now into paragon I settled on this formula for designing my encounters: 3-4 encounters at Level +2, with less chances for resting, and most challenges within level +2 as well. If resting is possible between those encounters, particularly extended rests I bump the encounter level to Level +3 or +4.

It's more dangerous, that's for sure, but the high intensity lends itself well to set piece battles which fit neatly in one session.

By way of compensation I use terrain powers as "accelerants", incorporate ways to recharge encounter powers into fights, avoid higher level monsters (particularly higher level soldiers) and use more lower level ones, adjust encounter difficulty on the fly (eg. "minions to spice"), and reward clever play with setting up their own ambushes or gaining a recruited NPC companion.