Should I allow a "Sahuagin trade tongue" as a valid option at first level? I tend to use the Sahuagin in plotlines, especially anything dealing with smuggling. I sorta use them like the Russian Mob is used in modern crime shows.
In 4e Sahuagin speak Abyssal, which is no longer an available 1st Level Language. I can appreciate the designers not wanting to have 1st level characters speaking to balors in their native tongue, but in Eberron Sahuagin aren't just underwater hobgoblins.
Should I allow a "Sahuagin trade tongue" as a valid option at first level? I tend to use the Sahuagin in plotlines, especially anything dealing with smuggling. I sorta use them like the Russian Mob is used in modern crime shows.
A few thoughts...
Barons and priests both can speak common. It's only the lower folk which are pure abyssal.
Any sahuigan who come into contact (peacefully) with other races would likely develop Common skills.
Incidentally, I had a blast when a party encountered a sahuigan priestess who could only speak in badly broken Common. Syntax was garbled, verb tenses were often missing, and she had a bet of a problem where she would use words in Common that weren't synonymous with each other, but they were in the sahuigan language. Like "He smells bad" and "He is hated by my people" are the same phrase in the Sahuigan dialect of Abyssal, so the party had a bit of trouble trying to translate why she was ranting about the people she wanted killed because they smelled bad.
And finally, PCs _CAN_ learn Abyssal. Take Linguist or the Mark of Scribing at any level besides 1. Is it stupid that a feat can allow a language at level 2 but not level 1? Yeah. But there it is.
EDIT: Oh, and double-finally: If you're going to house rule anything, why not just house rule they can learn Abyssal? I find that to be the lesser of two evil house rules, really.
Oh, and double-finally: If you're going to house rule anything, why not just house rule they can learn Abyssal? I find that to be the lesser of two evil house rules, really.
Well, I just don't like the idea that learning to talk to the "sharks" (which is the slang term I use in my Eberron for the Sahuagin) is the same thing as having a grand discussion with demons. Obviously the designers of 4e felt that Abyssal wasn't appropriate as a 1st level language, and required feats to get it for some reason. I don't want to break that assumption.
Given that I do, at times, like the role playing aspects of a party member being the choke point for communications. You can create interesting situations, like notes back and forth with the communication player. That way if the player has motivations to NOT tell the truth about something, he can do so. (DM Houses in my Eberron have a group which I call "Interpreters" which are kind of like Mentats from Dune. They're advisors and the like, but sometimes they form policy on their own by diplomatically changing the nature of translations).
I guess it just strikes me as odd that the sharks got lotted in with balors. Seems too big of an umbrella, especially that in Eberron the Sahuagin play a somewhat important role.
I do like the idea of broken English. That could be used with a player who has a valid background to understand the colloquialisms you were discussion. (Meaning a player who has had experience with Sahuagin could have a list of common expressions, and could relate those if he so chose).
As it stands I ignore the rule, especially for supernal [I mean, any creature that speaks Supernal tends to be able to speak all languages, so what is the point?], as it makes no mechanical difference.
which is the most absolutely idiotic language rule I've ever seen in any roleplaying game).
I don't understand the language hate here. Why is it nonsensical for part of your background to be "can speak X language"?
Suppose my character had spent all his time around a locksmith. But rather than choose to get a +2 in Thievery, I decided to get a +2 in Nature.
"But, it should be automatic for me, because I grew up around a locksmith!"
Well, yes: it SHOULD be automatic, because of your background. That's what backgrounds REPRESENT. In the case of your 'not learning dwarven by being raised by dwarves', well, it's a PCs choice to write one background and get the stats of another.
Just like I shouldn't write the background "Raised by a wizard and taught the basics of magic" and then write up a character with no ability in magic whatsoever, and then expect some sort of bonus ability ON TOP of my potential +2 Arcana from background/training in Arcana/muilticlassing that I refused to take. Backgrounds are an optional rules system designed to give PCs with odd backgrounds the chance to have mechanical benefits from them... such as non-dwarves speaking dwarven. Don't refuse your opportunity to learn dwarven from this background system and then complain that you weren't given the option to learn dwarven as part of your background.
Roleplaying reflects mechanics. Mechanics reflects roleplaying. If you decide not to take a racial language that, by your background, you SHOULD know... don't complain about it, just as I won't complain about my martial PC who SHOULD know magic from his background story, and doesn't, because I refused to take any magical abilities for him.
I find your argument flawed
Then I will elaborate. Read on:
Suppose my character had spent all his time around a locksmith. But rather than choose to get a +2 in Thievery, I decided to get a +2 in Nature.
"But, it should be automatic for me, because I grew up around a locksmith!"
The two are not comparable skill sets. Locksmithing is a trade, that requires not only natural dexterity but also a great deal of practice and practical knowledge. It simply is not possible to pick up lockpicking skills just by watching someone else do it. Furthermore, learning this trade usually requires at least one mode of communication in common with an instructor (frequently, a common language).
On the other hand, language skills can develop both passively (subsist in a foreign language environment for long enough and you will pick up an essential vocabulary and grammar) and actively (as with any other skill). Passive learning tends to stick in long term memory without any particular effort to file it - for instance, I picked up the Czech words for 'enter,' 'exit,' 'left,' 'right,' 'black tea,' 'please,' and 'butter' in the month that I spent in Prague, and I continue to remember those even ten years after my trip even though I've made no particular study of Czech since. I probably couldn't spell them with all the correct accents, but I at least remember them).
In the case of language skills acquired in formative years, the learning is almost exclusively passive and takes a very long time to fade, even if not practiced often (for instance, my father-in-law's first language was German, although you wouldn't think it to hear him talk - and he's still fluent even though he's used English in all his day-to-day communication for over forty years). Realistically, a character who was raised by dwarves would have to have been completely isolated from them for several decades before forgetting his native tongue to the point of being unable to communicate in it (cue retort that this is a game and doesn't have to be realistic - I know that, but languages are one of the things I have deep-rooted opinions about and I want the rules for them to make sense to me).
Actively learned languages fade, although they come back with exposure (my own German is getting rusty since the only people I can speak it with are my wife's grandparents, who slur their words so much that I can't understand them, but if I were to go and live in Germany for a year, I'd be conversationally fluent again within weeks). Hence why I don't have a problem with 'losing' languages from retraining the Linguist feat.
But a language that appears in a background would generally involve passive learning (I can think of exceptions, but by and large, the association of the background with it assumes enough regular use to make it stick), so it should be automatic rather than being a tradeoff between a learned knack and the communication skills necessary to acquire that knack.
The nonsensical bit is that it isn't automatic. You can choose it as your ONE choice from all your backgrounds, which means that any non-dwarf character who was raised by dwarves but who elects to take the +2 to Dungeoneering instead of the Dwarven language can't speak his 'native' language. This, to someone who knows exactly how hard it is to learn a language that you're constantly exposed to, especially in childhood (i.e. not hard at all), is absolutely ridiculous.
In that instance, I'd wager that the dwarves chose to spoke common (which all PCs get) more often than dwarven around or to the PC. It doesn't say you were raised by the other race from birth. You could have been introduced to their culture at any young age.
But, believe what you like - I've given my recommendation.
As a DM, I'd rule that you might know some basic phrases and have familiarity with the language as part of that background, but not enough for full proficiency. You'll get a +2 bonus to Insight if trying to roughly figure out what someone is talking about in dwarven. You recognize the dwarven language, both written and spoken, but only know basic phrases and can read only a few key words. Minor knowledge-related bonuses that don't need to be written down, like what most backgrounds give you.
My vote is, ignore the 4e language rules entirely (including that line in the background rules about a language being one of your 'pick one' background options, which is the most absolutely idiotic language rule I've ever seen in any roleplaying game).
FATAL exists bro.
Or you could rule that they speak goblin (or what have you) and abyssal is more of a language of the nobles and priests. I see no reason to overhaul an entire rules set when the porblem can be fixed with a simple notation to the monster manual entry.
Sure. Or any semi-common language. Or heck, They might even have chosen speakers who learn the language of those they trade or deal with. Imagion there are 20 "shark-men" on the deck of your ship along with a war chief and a "speaker". You've got to work out a trade for passage. You've never met this chief before, and you don't know the warriors from guppies. But you reconize the translator. He tried to con you once before and you taught him a harsh lesson. But now you have to trust that he's translating your offer to the chief correctly and not setting you up for revenge.
In my Eberron, the languages stayed the same. The total number of languages in your game world doesn't mater, just he languages that shows up in the campaign.
I'd have the sahaugin communicate by scent. 
It's easier to send smells and scents through the water than a voice.
I'd have the sahaugin communicate by scent.
It's easier to send smells and scents through the water than a voice.
(Real world physics) Not really, afaik a pressure wave (i.e. sound) travels through water a lot faster than a bunch of scent molecules will be convected. Also its a lot easier to send sound upstream than scent. (/Real world physics)
Of course there's no reason real world physics should apply to D&D, so if you want to have sahuagin that communicate by scent I'm not stopping you.
More on topic of the post, if you want level 1 characters to be able to communicate with sahuagin, but want to keep the invenstment requirement you could always just house-rule that you can take Abyssal at level 1. Hardly a game-breaking house-rule. If you only want your players to be able to speak to sahuagin and not to demons you could add a Sahuagin language or change their language to either Giant or Goblin (those two make most sense considering the history of Eberron IMO).
If you do start adding languages I think the thing to watch out for is devaluing the Linguist feat. If I were to add a lot of languages I think I'd change the feat so that it lets you learn the same percentage of existing languages. i.e. it now lets you learn 3 languages out of ten(?), so that's one third, if I were to add twenty languages (for a total of thirty) linguist would let you learn 10 (still one third).
(Real world physics) Not really, afaik a pressure wave (i.e. sound) travels through water a lot faster than a bunch of scent molecules will be convected. Also its a lot easier to send sound upstream than scent. (/Real world physics)
How about singing? Whales sing underwater. Since the sahaugin anatomy is based on ours, their larynxes need air in order to work. I think a sahaugin would have the ability to fill his or her lungs with air from their blood using some kind of reverse osmosis. They then use the air to sing.
Aquan would be based on singing. You sing in Aquan, but it works only underwater. I would suspect that the sahaugin and devils would not be able to understand each other since the sea devils would have to sing the infernal language. When they get out of the water into an airspace, then the sahaugin would be able to talk.
The OP was looking for a way for low level characters to communicate with Sahuagin without having to wait for later levels. Whale songs, color changing and sent based languages are all neet ideas but not very helpful for a 1st level character trying to ask a Sahuagin to please, please, not eat the cleric.
Pseudo-canonically (i.e. in a novel) sahuagin tribes have a designated member who knows Common whose duty it is to 'negotiate with' (read: extort) travelers who pass through their waters. While officially they offer their services as guides through dangerous waters, what people are really paying for is the assurance that the rest of the tribe won't attack and eat them on this trip.