I've been looking at running League games but I'm  being told that certain content like Eberron isn't compatible with other sourcebooks and adventures that relate to Forgotten Realms content.

Reading through it, I don't understand why.

For context, a lot of the D&D lexicon revolves around there being an Astral Sea between all the layers of the multiverse with Astral travel being able to connect to all planes of existence.

I understand that content published earlier probably didn't anticipate the content we have now, but I don't see why a GM cannot accept character sheets from other tables regardless of which books they were using besides a GM's personal preference.

Please can someone help highlight specific rules about this that override general rules in regards to League play with lexicon inclusion?

Thank you in advance and sorry if a stupid question.

Adventures League intentionally limits what's available to content in line with a given setting in order to ensure a cohesive experience for DMs and players

Remember that when you DM an AL game, your dm'ing for players who may well take their characters afterwards and go to a different AL table with a different DM. Just because you don't see a problem with Eberron content in the Forgotten Realms, that doesn't mean the next DM will feel the same.

So Wizards of the Coast creates a limit on what can be taken when playing in a given setting in AL (settings such as Eberron and Exandria have been featured).

Hi Davyd, thank you for the response, appreciated as always.

I still can't help but feel a strange limitation on that limitation. If a player came to my table with a Forgotten Realms sheet and I was using Eberron, it would be ok, but if someone came into a Forgotten Realm game from Eberron, it wouldn't be ok.

Have I got that right?

If so, that feels exclusive and not inclusive... and seems to go against the grain of what D&D is about, yes?

I'll take Warforged as an example.

Waforged have no place in FR. I would probably be willing to work with you to find a unique backstory so you could play one at my FR table, I'm pretty keen to help players make their characters work, but Warforged just don't naturally have a place in FR. By which I mean there's no history to explain why your Warforged was created. There was no war in which robots were pitched in battle against each other, so why is there a Warforged in this version of FR? You could argue about Spelljammer, but that raises other questions, does it not? Besides, Warforged are hardly congruent with the theme and style of FR. A lot of people won't like them in that world, if you're going for LotR style adventure, Warforged will rain on that parade.

If you find a DM running a private table that will accept your Warforged, then that's great. However, the point of AL is that it's standardised. What's acceptable in one is acceptable elsewhere that has the label AL. What's unique to Eberron is not universally acceptable in an AL FR game - or it wouldn't be unique to Eberron. 

I'm not familiar enough with Eberron or AL to comment on using FR stuff in Eberron, but it makes sense that Eberron-only stuff can't be used in FR. 

AL is like the McDonalds arches. It's a stamp to tell you what you're getting. It may not be the best table around in terms of rules, but you know what those rules are and you know what you're getting. Part of that is keeping settings to their own settings.

Why would Warforged exist in FR?

Easy. Plane shift, wizards, portals, deities, fiends, all mucking about with planes and time and space.

D&D is not a singular universe but a multiverse. There's an Astral Sea between each layer acting like Star Trek's idea of subspace. Keep going into subspace deep enough and you might eventually puncture the membrane into another realm. It's layers and layers, like bed sheets in your laundry.

Lord of the rings theme? Easy. Warforged can be big bulky brass machines made by dwarves; if ents and golems exist, then they could easily be a Warforged in disguise or just simply seen as a TV might be pretending to be a magical moving oil painting. In fact, it does say that Warforged can be made of wood, so why not have one that looks like a Treant?

It's not that hard to bring stuff from the future into the past and still keep theme and theatre. 

It's a question of being creative but still mindful of the adventures, NPCs and PCs around you while still respecting whatever the GM might've prepared as a story.

These are all reasons you as a DM might be okay with warforged outside of Eberron, but not all DMs would be. When you DM for Adventurer's League, you are DM'ing within a shared space and cannot unilaterally make decisions for all other DMs. It's Wizards of the Coast and the AL admins that make those decisions and AL DMs agree to them.

It's just the same as the fact AL DMs can't decide to give out whatever magic items they want, or freely hand out XP. Everything is dictated by the AL modules in order to ensure that differing DM'ing styles and opinions don't cause friction within the wider AL space.

AL D&D is not a place for 'being creative' in the manner you're using the phrase, because one DMs idea of creative is another DMs idea of disruptive. Instead, it's designed so that a player can drop into an AL game at one table, have a session, and then take their character with zero friction to another DMs AL table. Remember that the DM isn't preparing a bespoke story at each table.

Ok, so is there an official database of which DM is hosting which book and where?

I would hate to choose a book that only one GM three countries away is using at the moment.

If I want to make sure that my table is compatible as possible with as many other tables as possible, how would I know which one to choose?

I'm not an expert on AL, but generally speaking there are seasons and each season an adventure or set of adventures is approved. You don't need to be worried about what adventure you're running specifically though; as long as you're following the AL guidelines you'll be compliant with other tables.

For example, say it's AL season 13 and the official adventure series is (made up name) Tomb of the Great Sun, which has 5 parts, but there's also an AL sanctioned version of Wilds Beyond the Witchlight running. You could run any one of those 5 parts of Tomb of the Great Sun or Wilds Beyond the Witchlight and be AL legal. It's down to the players to decide if they want to drop into whatever you're running.

I would advise checking out the AL guidelines, or asking in the Adventurer's League section of the official D&D discord server

Quote from Ancient_Mutt>>

Why would Warforged exist in FR?

Easy. Plane shift, wizards, portals, deities, fiends, all mucking about with planes and time and space.

D&D is not a singular universe but a multiverse. There's an Astral Sea between each layer acting like Star Trek's idea of subspace. Keep going into subspace deep enough and you might eventually puncture the membrane into another realm. It's layers and layers, like bed sheets in your laundry.

Lord of the rings theme? Easy. Warforged can be big bulky brass machines made by dwarves; if ents and golems exist, then they could easily be a Warforged in disguise or just simply seen as a TV might be pretending to be a magical moving oil painting. In fact, it does say that Warforged can be made of wood, so why not have one that looks like a Treant?

It's not that hard to bring stuff from the future into the past and still keep theme and theatre. 

It's a question of being creative but still mindful of the adventures, NPCs and PCs around you while still respecting whatever the GM might've prepared as a story.

 That's great advice, for a private table. AL has a set of standards to standardise the game. As I said before, AL rules are like the MaccieD's of D&D. There are better tasting burgers, there are cheaper burgers, there are burger joints that are closer to me, there are even places that are better at every one of those traits, but I know exactly what I'm getting when I order a Big Mac, and that's a quality of its own. If I'm stopping by somewhere I've never been before, I'm a lot more likely to get a McDonald's than a random burger joint, because I know what I'm getting. People have their own ideas of what improves the game...and a lot of the time, they don't do anything of the sort. However, if I know an adventure is AL-compliant, I know what to expect and that it won't have odd rules or whatever that will ruin the game for me. Part of that standardisation is maintaining boundaries between settings. I'm in FR? No Warforged or Bloodhunters. No Kender. But that Orc Barbarian is going to go down without any issue at all, no concerns about the DM not liking it or annoying other players because they hate the idea of robots appearing while trying to get a LotR vibe going. Everyone knew what they were signing up for before they sat down.

Thank you, Davyd and Linklite, I appreciate the feedback. I think I understand now; it's about consistency. 

So if I stay on top of the season then I can get a good idea of what everybody that is running. Cool.

I'll keep reading.