Sammael said:
It should have, but it wasn't. Oh, did I forget to mention that they were fighting in darkness?
Yes, you did, and it makes a huge difference. That's at least a round of actions lost, where the enemy are unimpeded and the PCs are seriously hampered. (Incidentally, your DM was pretty kind about the situation - I would have thought retrieving torches and flint and steel from packs, and then lighting the torches should take more than one round, especially when done in darkness.)
Naturally, all PCs (five humans and a halfling) had magic items on them that grant darkvision. It took them a round to light torches (everburning torches don't work in antimagic, either). During this time, enraged grimlocks (who were barbarian 6, not fighter 6, sorry - I just double-checked)
This also makes a big difference - NPC barbarians are generally tougher fights that NPC fighters, since they can use their 1/day rage in every combat they are seen in (usually, only one), and since the combat is likely to end before the rage expires. The fighter's feats are generally less powerful, but last all day.
attacked with greataxes and power attack at +12/+7, for 1d12+11 points of damage. There were five grimlocks,
A grimlock barbarian 6 is CR 7. A beholder is CR 13. You say he didn't do anything except use his anti-magic cone, but that
is effective action - it removes the party items, puts the party at a severe tactical disadvantage, and nerfs the part wizard. Basically, it's an EL 14 or 15 encounter, which should be an effective challenge for 4 14th level characters, and leaning towards the deadly. Sounds about right to me.
Furthermore, the encounter was set up in such a way as to favour the enemy quite heavily. The enemy are pretty well optimised for the situation (stat boosts not reliant on magic, no magic of their own, melee combat types, able to see in the dark). This is not a flaw in the encounter - a beholder is likely to do just such things - but it does explain why it was so tough.
To be honest, I think this encounter went as I would expect.
and they had a pretty good chance of hitting just about every PC (the highest AC at the time was the party's main tank, with a +1 full plate and a +3 tower shield; without his deflection and natural armor bonuses, his AC was 23 - quite easy for grimlocks to achieve with primary attacks even after the light was lit).
And that's just one example of how PCs without magic are screwed. It didn't have to be antimagic; the party wizard could have cast mass darkvision, and an NPC equal to beholder's CR could have cast greater dispel magic on them.
Of course, the example is also not really a good indicator of how a low-item game would function, anyway. The anti-magic cone not only wipes out your items, but also the party wizard. This probably explains a lot of why you suffered so badly. If you remove the items but continue to allow spellcasting to function, the battle would work out rather differently.