To tell the truth, I never actually tried it, but it seemed like a pretty good use for a wizard with the multi-purpose rage ability.
The PHB says that while a barbarian is raging he can't use any abilities or skills that require patience or concentration, like moving silently or casting spells. I'm still don't understand why someone would cross class to a spellcaster just for a few spells. It's just seems like a waste when you could have the parties main caster use scrolls, wands, or just cast them. Or lacking any of that, low level potions aren't that expensive. For instance, a barbarian takes 4 levels of wizard and before entering combat he casts bull's strength, cat's grace, and mage armor. Nice bonuses to be sure, but he's giving up a max of 48 hit points, BAB, and possible extra rages per day among other barbarian abilities like damage reduction. That's giving up a lot imo just for 3 or 4 spells. Not to mention the fact that if your wearing armor you have a chance of a miscast. Better choices would be Rogue, for sneak attack, skill points, and reflex save. Or ranger for the 2 weapon fighting, and wilderness skills. Or even fighter for the extra feats.
In a PNP game, I had my rogue take one level of sorcerer. It gave him access to shield, expeditious retreat, detect magic, detect poison and read magic, which meant I could up my AC, run fast, and have some magical backup when searching for traps, as well as use wands and low-level scrolls without spending skill points on Use Magic Device and Decipher Script. It was a trade-off I felt worth it and worked out pretty well. How useful multi-classing various classes is depends on how you're planning to use it and how well the classes abilities compliment each other. I would probably never multi-class barbarian will a spellcasting class without a specific concept (such as a Barbarian/Bard for a Skald), though I suppose a Barbarian/Druid could get pretty nasty by wildshaping and then raging.
No true strike? Ok rules guys, what about a spell where you cast it, it hangs around for a while til u touch something, then you rage - does the rage negate the spell? I mean in your rage u r thinking, "i just wanna get my hands on them!!!" ie make a touch attack
I would say the spell sticks around through the rage because you're not casting it while raging. If the spell requires concentration, however, screaming like a loonatic while thinking "Kill! Kill! Kill!" is going to break it.
Barbarian Rage is supposed to be where a barbarian transitions to a state of total anger [the rage] in an absolute bloodlust and desires to kill everything where it stands. There does not have to be lunatic screaming, just a barbarian completely consumed with feeling compelled to kill everything in sight and wanting everything dead.
One level of spell caster with a combat character... Kalshane is right about using a spellcaster for one level. If the character has his/her 2nd level as a mage or sorcerer then you have access to those spells. i use toffee without a mage or sorcerer. it sounds wierd, but the tanks can get scather and frag and close with any bad guys. plus your cleric ( a must) can be multi classed with fighter or ranger and get the bast. swr prof. then the two characters have some charm spells from the fighter/sorcerer (true strike etc) and a cleric that can use scather/frag. a high intell. cleric is needed so he/she can have higher interaction skills. have the fighter be high intim. so the cleric doesn't have to raise his/her intimidate. if you start the game after loading a last fight with the lady of fungi, your 2 or 3 characters with max out the first level when you start the game. you won't need any npcs to steal away your experience points. the 2 or 3 characters can be 7th level before they make it to the temple.
Hill giants would make poor Monk's. With a base starting wisdom of 6 and a dex of 10 they would lose most if not all of the Monk's special abilities. I think a better choice would be 1/2 Ogre. They still take a hit in dex and wisdom, but with high rolls it might be possible.
how about a troll monk? or are they as skill lacking as hill giants. (that would be cool to see a hill giant to use martial art moves, it look so weird, almost like a hill giant wizard too. ?)
Well besides the alignment problems, I would have issues letting monster races be certain classes. Being a monk takes total dedication, the chaotic nautre of most monster races would make it very difficult for them to be monk's. Monk's are like Paladins in a way, most humans can't meet the strict guidlines that those classes require. In the PHB it says that dwarves, halflings, and 1/2 orcs find it difficult to be a Monk, how much more would it be for something like a Troll? And besides all that it seems rather munchkinish too me.
Besides, You wouldn't "see" those monster races doing martial arts moves, as there isn't Monk animations in the game for these races to use, they'd still use thier un/armed attack animations.
A LOT harder. Aside from the chaotic nature of trolls (which you aptly mentioned) they are brutish and none too bright. Certainly, they lack almost every single quality one would find in a monk character.