I'm having some trouble with my group, generally in the optimization priorities between players and appropriate numbers in encounters.
We have one player who IP-proofs is characters as much as he can. He always strives to be at least 10 higher AC than the highest known attack roll, have attack (or trip/grapple) rolls 10 higher than the highest known enemy opposed roll, etc. So far, we've kept him challenged by attacking him with immune creatures, but the immunities are getting less relevant as he gains items to counteract them, and they weren't really satisfying, since he pretty much couldn't interact with many of them. (FYI, this is
The Monk Who Couldn't Decide build, which is doing surprisingly well at level 9. The link is outdated though.)
Another player is newer, playing a Astral Construct psion. He's our baseline. His ACs are about the same power as the average enemy bruiser, and he isn't using any recharge tricks, so he plays conservatively.
The Wizard is an Elven Generalist/Spellfire Channeler (Channeler being given full casting progression). Basically just a control wizard who eats wands to nuke on occasion.
The last player is a
Warforged Gish, focusing on the Arcane Lightning+Fire ring combo with Wreath of Flames. He just walks up to things and does 12 or more d6 in an aoe around him.
One player who can ignore combat rolls, one player who is average, and two players who can spontaneously drop enough damage to kill off most creatures without trying. Depending on the encounter, the ability of the team varies from (CR=Group ECL) to (CR=Group ECL+3). This sounds great, except that it is entirely random when the power shifts. The psion is the most common no-show, so it's not an optimized player not attending. It just seems to be a matter of them walking all over encounters until they hit a perfect storm of enemy abilities that completely screws the party.
Notable fights:
• CR 10 taken out by an explosive rune book (party was VERY shorthanded that day. Level 7, only 2 players)
• CR 13 taken out by the wizard's shivering touch.
• Monk dismantled an entire encounter because he had AC high enough to ignore the attacks of every enemy in the room, went in alone, and closed the door behind him.
• 2 people failed a saving throw for an inhaled paralysis poison at the start of an under-CR fight, almost ended up in a TPK.
• Party attempted to kill off an entire room of enemies by dropping a fireball through a skylight. The enemy boss was incorporeal behind them, collapsed the roof, and dropped a cloudkill into the rubble.
• 3 Party members failed save vs a Mind Blast, getting stunned for multiple rounds while Vrocks performed a Dance of Ruin.
(We are gentlemen about breaking the gentlemen's agreement. Explosive Rune books and Shivering Touch are now established tactics in the campaign world.)
Note that none of these ended up feeling like fair fights. The balance point swings from too easy to too hard with the slightest nudge, and the balance point continually changes based on the Wizard's spell loadout and the RNG of the player's saves vs crowd control.