Welcome to the Chromanexus

The Chromanexus is a "West Marches" style campaign set using the Dungeons & Dragons 5th Edition (5E) ruleset to govern regular gameplay. You don't have to have the rules memorized, but we do recommend at least getting yourself a copy of the basic rules (click here to get them free on D&D Beyond) for referencing.
Generally speaking, we do our best to honor rules-as-written, or "RAW", gameplay. There are a few exceptions where an outstanding rule doesn't work in our game environment so it's been changed - otherwise known as "homebrew" or rules-as-intended (RAI), depending on the context - but we do try to keep it consistent enough that people can reliably know how to play the game and interact with each other even if one of the "Game Masters" (staff who run the whole server) isn't immediately present in one of your many sessions or threads.
Lastly, we are a play-by-post campaign (explained below), using Discord as our medium for gameplay. It's safe to assume you got here from there, but if you haven't joined the server yet, you can find us at https://www.discord.gg/Chromanexus to hang out or play.

Adults Only, Please

Other roleplay sites and games often leave content open-ended in a way that permits children to play. While we don't typically get graphic on the server, we definitely discuss adult topics and themes both in- and out-of-character and so, assuming you're already read and agreed to the server rules, we require all players be at least 18 years of age or older.
In the same vein, to avoid unnecessary conflicts of interest in the game's structure and content, we require all characters to be adults of their respective races. While children are not non-existent in the universe, and there are certainly childish adults out there, we do not let players play as literal children, for more reasons than we care to list.
Adults only, please.

What is Play-by-Post?

For those unfamiliar with the term, play-by-post (PBP) is a format of play where rather than gathering around a physical or virtual table to play at regular sessions, we instead use the equivalent of text messaging back-and-forth to dictate our character's actions, inner monologue, and narration of the game world. For veterans of the play-by-post community, you may recognize this as a modern parallel to old-school forum games, which operated much the same way.
So, aside from writing instead of speaking, what can you expect to be different? For starters, gameplay tends to be much slower than a normal game. What might be done in a single sitting at a more traditional table might take a few days or weeks to finish in a play-by-post environment, as people's varying schedules mean the typical player won't be able to respond more than once or twice a day, if even. However, in exchange, gameplay tends to be much more laid back, people can more comfortably come and go from the server as their real life schedules shift, character development is far richer as we have the time to think about our characters' interactions, and players who might not otherwise speak up or consistently attend a regular game have an equal chance to participate and let their characters shine.
As an added bonus, since we use Discord as our main tool for the game, administration doesn't need to worry as much about site maintenance, making it easier for us to join you and play too!

What is a "West Marches" Campaign?

In a few words, a "West Marches" campaign is a story or adventure set that does not center on any one party in particular. It can be boiled down to these three points:

• There is no regular group of players. Missions instead pull from a larger pool of available players for each mission.
• Each mission is entirely self-contained (starts from base or an agreed upon point-of-origin and "ends" in the same place, or at least ends in a safe place).
• There's generally a focus on narrative and exploration over a set storyline with a pre-ordained path for the party to follow. There may be a greater story to follow along with that also flavors how individual games are run, but it is otherwise something to be discovered more than run through.

In a typical game, the same few players and their characters contribute to the story as defined by the game master. In a west marches campaign, there may be several players who rotate in and out of one or more parties run by one or more DMs. There may be a single connecting story across the greater world, but often these campaigns are divided into several shorter, more digestible quests and missions that may or may not be related.
As this question comes up a lot with how expansive the game lore can be as a result: You do not need to keep up with everyone's stories to participate in this game. In fact, you technically don't have to keep up with any stories to play along with everyone (though you should probably at least know what your own characters have done). Some players are only aware of whatever they've covered in roleplay, in order to keep themselves honest and avoid their character knowing things they shouldn't know (see metagaming below). Others just enjoy reading and seeing what everyone else is up to, and can glean insights about the game world to enrich their own characters in doing so. The point is, neither is the wrong way of thinking. We just want you all to come, hang out, and have fun playing some good ol' D&D with us.

Supported Content

In addition to the basic rules, we support all official D&D 5E content. The Player's Handbook (PHB), the Dungeon Master's Guide (DMG), and any additional adventure or source books published by Wizards of the Coast. We also support Critical Role and Magic: The Gathering content.
Unless you have a personal interest in purchasing this content, don't worry too much about needing to get your hands on copies. Using D&D Beyond, we host a few digital lobbies you can join that grant access to everything we've purchased to-date, provided you add a character to the lobby. We'll explain how to do this later.
We do not support Unearthed Arcana (playtest material), One D&D, Acquisitions Incorporated, or third party content (such as the Rick & Morty adventure book). If you use one of our campaigns to host your character sheet, then these will be disabled by default.
If you're ever unsure about whether a particular book or rule you've found is legal or supported for play in the Chromanexus, check with staff in the #blame-a-gan forum.

Beware Metagaming!

Metagaming, also called power playing, is a concept of using your personal knowledge of the game and its ongoing events to allow your character to do things they would not normally be able to achieve, or even to manipulate or force another player's actions without their consent. Common examples include:

• Dictating the actions another player or player's character should take without prior permission. Example: [Player], you play a cleric. You should be casting bless on all of us. [Player], you're playing bladesinger wrong, you should be playing [insert hyper-optimized build here].
• Acting on information your character may not reasonably know, also called "player knowledge". Example: loudly proclaiming "That's not a celestial, it's a force cat!" when encountering an enemy that has only been described in-character as a celestial, while the player knows from its stat block that it is not, in fact, a celestial. Also up for consideration: assuming that a given character (player or otherwise) is evil or up-to-no-good, in spite having no evidence and/or dice checks suggesting nothing is wrong or amiss either, because you "just have a hunch". 
• Intentionally pursuing character traits and features in a way to create combos or results the game never intended a player to have in order to gain a distinct advantage in applicable scenarios. Example: Why yes, we have in fact read about hexadins, we know the memes, and no, they're really not welcome at any table that might actually want to play the game.

The reality is a little bit of metagaming is unavoidable. There's really no way of being certain whether you're using fire damage against the troll because you know its weakness, or if you just happened to use fire damage because it's  one of your main attack options. Sometimes people discover character builds that allow them to be insanely versatile and consequently having the answer or solution to every single problem the party encounters. Again, these are scenarios that can occur naturally for no other reason than they're possible. 
Many of us on Chromanexus have been playing or GMing games for years. We know.
Where it becomes a problem is when the player is ticking one or more of these boxes with noticeable intent, and using them in a malicious manner - especially if they've already been warned to stop doing it. 
As part of playing on Chromanexus, we just ask players to be aware of their in-game behavoir and take steps to avoid causing a problem before it becomes a problem. It's one thing when your character's story is to become "the greatest swordsman in all the lands", and you actively pursue storylines and pick traits to support that story; it's another thing to go out of your way to pick features and options that make an unkillable murder hobo (someone whose solution to every problem is kill first, kill later) that actively goes out of their way to create conflict even in situations where there isn't any and get confused when no one wants to celebrate your legendary skills. One is someone actively trying to contribute to the table and the game's story; the other is going to drive everyone else at the table away to other games, assuming you're not asked to leave first. 
Even then, it can be a gray area, and hard to tell the difference at a glance. If there's ever a concern that something you are doing might be considered metagaming, ask! Staff take great effort to maintain a fun and fair game environment for everyone and are happy to share advice, tips, and tricks to avoid it.
That said, metagaming itself - intentional or not - is explicitly against the server rules. We operate on a warn-and-strike system, as outlined in the server rules and conduct channel.