It's the difference between seeing this game as a story versus a number-crunch stat sheet. After all, that's why people play Warforged in the first place; it isn't fluff, it's power-gaming that makes realistic role-playing next to impossible, like walking into a tavern with a Tiefling.

Oh I love when a player demands they want to play XXX ... so you allow it. Then when they arrive in a town, children run from them, others in the town demand they leave or "Your sought aren't welcome around here ..." and the like.

Then the PC complains you're being harsh on their "individuality" ... or they set their Charisma to 5 ("It's not a dump stat, I just see them like this") and then once again complain because the other players are roleplaying that they don't want to have anything to do with the poorly behaved / smelly / halitosis / super ugly character ...

So a Tiefling walks into a bar ... and then gets thrown out immediately

here is the problem... unless everyone bends/breaks the intent of the rules then anything that the DM has to do to challenge a single player hurts the rest... its a ballance game. Break the ballance then it makes the game unejoyable for the DM...

Help keep the DM from having doing stupid things just to challenge a character...

Now that is unfair to the Tiefling... they are only to have one or two ununsual features... they dont have too look like a pit spawn... and they dont have to be evil... not a PC one...

Also I have seen warforge be characters not a bunch of numbers... like a warforge bard... or a warforge cleric... or the best and most unusual one I have seen... Warforge Druid (He just wanted to be a real boy...)

warforged are the dumbest idea in D&D

There are a lot of ideas that are even dumber than the war forged. DnD is famous for glaring gaps in rules. Not to mention ideas that literally just scream WTH. I have seen a player use mage hand to do unspeakable things. It is a problem when your answer to a problem is there is no rule against it. Yes the regeneration is possible for your character to get and I personally would endorse it.

Actually there are rules against anything that the DM does not want in... Every book except the PHB and DMG are listed as OPTIONAL rules... if you dont want to allow in Reserve Feats they are an optional rule. Class substitution is an Optional Rule... Spells from the Spell Compendium of Crack are optional... This was the hardest of all the concepts I had to get across to my group... I dont have to allow anything in at all... OK, getting the idea that Sorcerers where untrained magic casters and hence were witches and needed to be burned to the stake was a bit harder (my campaign setting) but none the less... Optional is optional... I have to approve each item someone gets from a non-core... and use the power of NO alot... and if they dont like it... I dont have to let them trough my door...

In fact, you don't have to allow anything core either.

The rules are there as a foundation so that everyone has a starting point from which tom work. The GM can refuse to allow other rules, he may choose to allow some and refuse others. The GM may, in fact, as Bbender has just said, even change the core rules as long as the players know and understand what they're letting themselves in for.
GM's world, GM's rules. Don't like them, don't play. Sure, ask away, but once the GM makes a ruling, you live with it. Or leave.

The long story short about this entire thread seems to be "Rule 0: The DM is always right, no matter what pages 1, 21, or 131 say." But this guy started this thread in October... I think he either got his character already or didn't play