Analog Games.

that sounds like a cool game XD

So, I might be getting into a local DnD campaign. I was looking at some Lovecraft art a couple of days before considering joining, and I decided, if possible, to get a carnivorous, half-fish race to play as to make a burst DPS rouge out of to mimic the turned Innsmouth residents from Call of C'thlu.
I found this race, the Sahuagin. As a race loosely related to sharks, they are savage, predatory creatures, but sapient and fairly intelligent. They favor barbarians, but their savage nature would fit my burst DPS rouge build fairly well. Their major drawbacks is that they are light-blind and water dependent, not to mention that your ugly mug and aggressive nature doesn't help your charisma at all.
I was thinking about how this character would act, and then I realized that as a carnivorous, monsterous race the size of a human and from a culture that supports the idea that other non-predatory races are entirely inferior to them, he would have absolutely no qualm cannibalizing people he kills. If my DM would allow this, my group probably wouldn't need to feed me and I could heal some after every battle. To top this off, one of the house rules of the group is that water dependent characters can stave off land drowning by drinking water, which resets the timer on the drowning. Blood is mostly made of water, and is more oxygen rich than most liquids, so drinking someone's blood should stave off land drowning for at least as long as when I take a drought of water. And on top of that, imagine how terrifying it would be to have a creature with a maw dripping with the blood and gore of one of your allies leap out of the shadows to attack you?
Basically, if I could convince the DM that these effects are relevant, then I could both be the most self-sustaining member of our group, one of the most terrifying people in the campaign, and fully fulfill my mimicking of the turned Innsmouth residents.

And then I discover that that race was NPC only in standard DnD. Dagnabit.

talk it trough with the DM, if your idea doesn't clash to much with the other players/ campaign, maybe you can work out a way to do it together.

From my (minimal) experience GMing, so long as it's not horribly out of place or gives an unfair advantage, most people would be cool with it.

So, Innsmouth resident character is a go. Now, time to design the character himself.

good, my DM often tells us that if a character concept is cool and not broken then he usually allows it. by the book rules usually dictate that playing a monster race takes far more xp to level up because they have unfair abilities compared to other player characters. like for example a doppleganger or a half dragon would have to level up twice before they level up once. 
that's meant to deter players from playing broken races, but talking to the dm you can make a deal and be fairly unbroken to the other players while still playing your race of choice.

one thing i will say to someone who hasn't played tabletop dnd before, all the players are heroes (antiheroes or villains or whatever) of the story, you have to share a spotlight though there will be times when another player may so something amazing, there will also be times when you do amazing things. but above all have fun, if things stop being fun then there's no point in playing. it is after all just a game and things happen in games where sometimes characters die, it's always sad when that happens but it does happen. accept the losses, the bad rolls and move on.
like i said before, have fun. fun is the most important thing.


kinda off but kinda on the same subject. recently i ran a session of world of darkness, which is a tabletop rpg that takes place in modern times in a world full of supernatural creatures. during the last session one of the npc's decided to betray the players and called the police on them. what ended up occurring was a stealth challenge where the players had to sneak away from the cops through a cemetery. 3 of the characters escaped, and 3 were caught. since the players didn't outright attack the cops, the cops simply arrested them.
one of the players was so pissed off that his character had failed to escape that he threatened to have his character commit suicide, so i told him "this is a game. if you aren't having fun then stop playing." 
he proceeded to blame me, the GM, for his failure. 
future sessions with this player are going to be less fun now because he can't accept failure.

Another good rule:
Try not to be become too powerful, as it's always possible even within standard rules.

Okay. So the group I'm GMing currently have this problem. Power gaming started happening. It's partially my fault. I made a boss slightly too powerful to kill normally, and one or two characters probably would have died to take it down. To be fair, it was my first real boss battle I'd made.
Still, I thought fast and dealt with it and didn't penalise them.
I just made their NPC friend (A slaver they forced to work against her former allies/friends by death threats, who was now depressed due to her betrayal) load up on explosives and kamikaze it.

I'll admit it may have been jarring to see a NPC commit suicide/noble sacrifice like that, but I really wanted her out of the party and had warned them about this sort of action being likely, (I was already controlling 2 party members at the time, a third was too many) and it made sense in character (she had helped kill literally every friend she had) and it fitted the setting.

This unfortunately, has left the party in a state of fear only solvable by power gaming.
Christ.
One of them figured out how to automatically get the party to go first unless sneak attacked, but since he can automatically detect any creature, living, dead, machine or otherwise approaching unless magically hidden and even then they have a decent chance of being spotted, that's kinda impossible too.
It makes it hard to make interesting battles, I can tell you.

Bowen wrote:Another good rule:
Try not to be become too powerful, as it's always possible even within standard rules.

Okay. So the group I'm GMing currently have this problem. Power gaming started happening. It's partially my fault. I made a boss slightly too powerful to kill normally, and one or two characters probably would have died to take it down. To be fair, it was my first real boss battle I'd made.
Still, I thought fast and dealt with it and didn't penalise them.
I just made their NPC friend (A slaver they forced to work against her former allies/friends by death threats, who was now depressed due to her betrayal) load up on explosives and kamikaze it.

I'll admit it may have been jarring to see a NPC commit suicide/noble sacrifice like that, but I really wanted her out of the party and had warned them about this sort of action being likely, (I was already controlling 2 party members at the time, a third was too many) and it made sense in character (she had helped kill literally every friend she had) and it fitted the setting.

This unfortunately, has left the party in a state of fear only solvable by power gaming.
Christ.
One of them figured out how to automatically get the party to go first unless sneak attacked, but since he can automatically detect any creature, living, dead, machine or otherwise approaching unless magically hidden and even then they have a decent chance of being spotted, that's kinda impossible too.
It makes it hard to make interesting battles, I can tell you.

we used to have some power gamers in the group. they made up BS races and and used BS cross classes to become super powerful. one of them did this in my first dnd game in which i was a DM. so i was unaware of how broken it was until we were actually playing. it made things unfun for everyone because he outshined the other players by far too much. it wasn't until the normal dm (who was away) came back and learned what had happened then he told the rest of us that this guy had basically cross classed and powergamed his character to the point that it could be called cheating. so i told him he couldn't join my games anymore.
there's this other guy who still plays some dnd style games with us who powergames, but i don't let him into my games either.

i'm not sure how it is that your group got so into powering up their perception (or however it is they sense enemies incoming) but it might make it interesting to have Blink creatures or teleporting creatures attack the players. like shadar-Ki.