Mercule
Adventurer
I have a few. 
No halflings -- especially no kender halflings. Kender is a race found on Krynn. They steal all sorts of stuff. Halfling is a standard D&D race and are fairly boring. I can't really fault you for wanting to take the 2D personality of kender and inflict it on halflings, but it doesn't belong there. Also, I've seen kender played that we better at being a kender than Tas was. I'm done with them; sucks to be you. Non-kender halflings are painfully bland and uninteresting, also. Literally any other size small race would be more interesting. From the PHB, your option is gnome. Gnomes are like halflings that don't completely suck. This rule gets an exception for Eberron and Dark Sun, where the halfling races actually have a point (even if it's questionable in Eberron).
Any gnome that starts playing with mechanical stuff is immediately struck down by some uber-divine force. Why? Because tinker gnomes sucked in Dragonlance. They suck even more outside of Dragonlance. Gnomes talk with squirrels and badgers, not machinery.
No gender-bending. I'm not actually opposed to the idea. It's just that 90%+ of my experience has been with sexually repressed, misogynistic, social maladepts who wanted to play a whip-using, leather-clad, alpha drow vixen. While it's been years and years since I played with anyone who I think would make some sort of sexual projection, it's also been years and years since I've had anyone ask. The rule remains in place only because I wouldn't roll the dice with a new player's first character at my table. If you're a creep, I'd rather figure it out in some way other than you putting your fetishes on display in front of my 13 year old daughter who is part of the gaming group.
No drow. They were interesting, at one time. That time was the mid/late 1980s. At this point, they make kender and tinker gnomes look positively fresh and interesting.
No gunpowder or steampunk. I don't mind steampunk, as a genre. I just don't want it in my D&D. I don't really want gunpowder in my fantasy, either. If you like it, good for you and I won't criticize. Just not a game I'm interested in running. I might play, though.
No magic-marts. Even in 3E Eberron, I didn't have these for adventuring gear (everburning torch or Murlynd's spoon, sure; made-to-order +3 sword with flame and poison damage, not so much).
Clerics get their magic from their gods. If you can't be bothered to advance your god's goals and consider his doctrine, he can't be bothered to give you spells. Eberron is the exception to this rule because of explicit setting guidance. Even there, you ain't playing a Cleric of a philosophy or similar.
Druids don't worship gods -- at least not in the same way a Cleric would. Details vary by setting, but the same god will not have both Cleric and Druid priests. In my home brew, Druids are animists.
Alignments are squishy. I still use them, but there are really two levels of each -- nominal/marginal and intentional. I used to use "unaligned" for the nominal level, but found that it was actually a good question to at least ask the players.
Related to that: As the GM, I'm the final arbiter of any morality scale/mechanic/assignment. In D&D, I don't penalize (most) characters for changing alignments and have no restrictions on playing evil characters, etc. This rule really came about while running WoD (Vampire, specifically), where there are consequences for changing your moral compass. We can have all the conversation around politics, religion, etc. in the real world, but I want to keep the game moving without arguments during the game. I will tell you when your actions disagree with whatever morality scale the game is using, in a manner that lets you reconsider taking those actions. You can relate what you're thinking and if there's extenuating circumstances, but my decision will be final, once made. For D&D, that just means that I may tell you that you're CN instead of CG -- but that's descriptive, not prescriptive; just keep on doing what you were doing (if you think your PC is Good and I tell you he's Evil, it may be appropriate for one of us to do some soul searching).
No halflings -- especially no kender halflings. Kender is a race found on Krynn. They steal all sorts of stuff. Halfling is a standard D&D race and are fairly boring. I can't really fault you for wanting to take the 2D personality of kender and inflict it on halflings, but it doesn't belong there. Also, I've seen kender played that we better at being a kender than Tas was. I'm done with them; sucks to be you. Non-kender halflings are painfully bland and uninteresting, also. Literally any other size small race would be more interesting. From the PHB, your option is gnome. Gnomes are like halflings that don't completely suck. This rule gets an exception for Eberron and Dark Sun, where the halfling races actually have a point (even if it's questionable in Eberron).
Any gnome that starts playing with mechanical stuff is immediately struck down by some uber-divine force. Why? Because tinker gnomes sucked in Dragonlance. They suck even more outside of Dragonlance. Gnomes talk with squirrels and badgers, not machinery.
No gender-bending. I'm not actually opposed to the idea. It's just that 90%+ of my experience has been with sexually repressed, misogynistic, social maladepts who wanted to play a whip-using, leather-clad, alpha drow vixen. While it's been years and years since I played with anyone who I think would make some sort of sexual projection, it's also been years and years since I've had anyone ask. The rule remains in place only because I wouldn't roll the dice with a new player's first character at my table. If you're a creep, I'd rather figure it out in some way other than you putting your fetishes on display in front of my 13 year old daughter who is part of the gaming group.
No drow. They were interesting, at one time. That time was the mid/late 1980s. At this point, they make kender and tinker gnomes look positively fresh and interesting.
No gunpowder or steampunk. I don't mind steampunk, as a genre. I just don't want it in my D&D. I don't really want gunpowder in my fantasy, either. If you like it, good for you and I won't criticize. Just not a game I'm interested in running. I might play, though.
No magic-marts. Even in 3E Eberron, I didn't have these for adventuring gear (everburning torch or Murlynd's spoon, sure; made-to-order +3 sword with flame and poison damage, not so much).
Clerics get their magic from their gods. If you can't be bothered to advance your god's goals and consider his doctrine, he can't be bothered to give you spells. Eberron is the exception to this rule because of explicit setting guidance. Even there, you ain't playing a Cleric of a philosophy or similar.
Druids don't worship gods -- at least not in the same way a Cleric would. Details vary by setting, but the same god will not have both Cleric and Druid priests. In my home brew, Druids are animists.
Alignments are squishy. I still use them, but there are really two levels of each -- nominal/marginal and intentional. I used to use "unaligned" for the nominal level, but found that it was actually a good question to at least ask the players.
Related to that: As the GM, I'm the final arbiter of any morality scale/mechanic/assignment. In D&D, I don't penalize (most) characters for changing alignments and have no restrictions on playing evil characters, etc. This rule really came about while running WoD (Vampire, specifically), where there are consequences for changing your moral compass. We can have all the conversation around politics, religion, etc. in the real world, but I want to keep the game moving without arguments during the game. I will tell you when your actions disagree with whatever morality scale the game is using, in a manner that lets you reconsider taking those actions. You can relate what you're thinking and if there's extenuating circumstances, but my decision will be final, once made. For D&D, that just means that I may tell you that you're CN instead of CG -- but that's descriptive, not prescriptive; just keep on doing what you were doing (if you think your PC is Good and I tell you he's Evil, it may be appropriate for one of us to do some soul searching).
