I am having trouble with the temple guardian in the jungle. Arrows work for a little while and magic missile seems to be the best weapon I have. Any pointers?

umm...there's another thread in here someplace on this...but +3 weapons or better, and chain lightning seem to be the best bet. If you can summon shadows and elementals they'll hit him too.

I had my sorcerer cast stoneskin on all my character, that helped a lot. Emotion: Hope, protection from evil, and other protections spells helped a lot too.

If you like cheesy tactics, consider casting a tons of Skull trap and delayed blast fireball on the spot where he spawn.

Try doing sneak attacks at the start. The dragon has approx 400hp so any little head start helps. As mentioned, you need +3 weapons.

Also, instead of boosting the party, try to super boost 1 or 2 characters. It is hard to hit the dragon, but if one character is constantly succeeding, you will wear him down. The dragon also concentrates on 1 character at a time so if you have a weak character getting attacked, run away with him & then send him back in when the dragon turns to attack someone else.

Hasting all your party works & having some temporary peons around to get killed takes some of the attention off your party. Of course, the spell for acid resistance is nice too...

1st use protect from evil to all the party
2st send one of your fighter to the font line
3 use Otiluke's Resilient Sphere to protect him and attract the dragon
4 use water element to help melee attack
5 use Mordenkainen's Sword attack form distancd
6 use Mordenkainen's Force Missiles

you can kill the dragon easily