I've asked several times what function a monk serves and the most general answer has been
For the most part (IME) the rogue is the second best... at a lot of things.
I play a rogue, when I go scouting, I often take the monk with me. He isn't as good, but pretty close, and I get back up that won't blow my cover.
When fighting, the fighters are better; but the monk sure can come close to keeping up with them.
When the will save from the (insert whatever monster) has to be made, a few of the characters make it. The monk is almost always one of those.
That firetrap is a drag, except that the monk with good save/evasion ignored it.
No one likes getting plugged by an archer, except the monk can deflect them, and move fast enough to close the distance.
The bad guy was making a break for the door. Luckily the monk was able to catch him. (grappled him to the floor)
As a thief I can tumble to the bad guy, but now I am alone. Oh wait, the monk can tumble with me... and now there are two of us, and I can also SA.
The monk likes to grapple/pin, and then I can SA. It is a great team up.
Watch out for that pit trap, oh never mind, you have slow fall.
Plus, set up situations where slow fall is useful, when trying to trap someone, or get away from someone. Roof tops are cool.
Stunning fist, DC 18... pretty useful. (even the hill giant has a 25% chance of blowing the save)
Then looking a little into the future.... you get to heal yourself. You get to automatically make certain reflex saves, and may still take no damage. Not to mention poisen immunity, dimension door, and spell resistence.
I think the monk shines on its own. It just sounds like what you *want* to play is a front line tank. That is cool, and pretty fun. But that is not the role of a monk.
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