The title is only half a joke. Okay, maybe a bit more than that.

The Sanctuary Bastion Facility allows you to cast healing word one time within 7 days after you take a long rest within the Sanctuary. With an extra addition.

After spending a Long Rest in your Bastion, you can cast Healing Word once within the next 7 days without expending a spell slot. The spell’s level is half your level, rounded down.

The spell's level is half your level, rounded down. That makes perfect sense, since that's how full casters calculate their highest level spells and spell slots, so the spell given by the Sanctuary will constantly scale itself to be more-or-less cutting edge for the party. But normal casters have an exception to this rule; they stop at 9th level spells. This rule has no such limitation. This means that a 20th level character who has taken a long rest within their Sanctuary within the past 7 days can cast healing word at 10th level.

Thoughts? Mechanical implications? Rules lawyering?

I mean, purely in terms of Healing Word all that means is one extra d4. I’d probably just put this down to a minor oversight when writing the description, or the assumption that “up to 9th level” would go without saying.

Well, imma be just plain old and say something like, i dunno, "well, when I was young, we didn't have these fancy things. There were only nine levels of spells, and only one group could use the highest two, and there was none of this flim flammery!"

or I might be grouchy and mutter about how we already have 10 spell levels, since cantrips are effectively level 0.

Or I might try to be pissy and point out that "we don't have all that many 9th level spells so why in the world would they try to introduce all of what, two 10th?"

Or I might just look at that and shake my head while rewriting the whole damn thing.

The new twinned spell also let’s you cast spells effectively at 10th level.

Quote from AEDorsay >>

Or I might try to be pissy and point out that "we don't have all that many 9th level spells so why in the world would they try to introduce all of what, two 10th?"

I doubt we're going to see actual 10th-level spells, but upcasting beyond 9th doesn't really seem like a problem; most spells are at their best value at the level they start at, very few scale up well into higher level slots compared to what you could be using them for.

You don't see many people burning a 9th-level slot on healing word, as it's just not worth it for an extra 1-4 hit-points, in fact it's arguably not worth it to upcast it at all; just cast it at 1st-level when an ally goes down to get them back in the fight for a turn, then rinse and repeat when they go back down again. Not that a free 10th-level cast is terrible, free's free, as it's not competing with something else.

Even spells with 1d10 damage aren't all that amazing upcast; the main reason to upcast a damage spell is if the average damage at a lower level might leave enemies alive on a handful of hit-points, so you upcast a level or two to guarantee kills.

The more problematic upcast spells would be those that can have multiple targets, and even then I'm not sure it's all that broken really.

Quote from AEDorsay>>

Well, imma be just plain old and say something like, i dunno, "well, when I was young, we didn't have these fancy things. There were only nine levels of spells, and only one group could use the highest two, and there was none of this flim flammery

Didn't spells go up to 12 in the old days?

Quote from Mephista>>

Quote from AEDorsay>>

Well, imma be just plain old and say something like, i dunno, "well, when I was young, we didn't have these fancy things. There were only nine levels of spells, and only one group could use the highest two, and there was none of this flim flammery

Didn't spells go up to 12 in the old days?

 
Not in 1e/2e (AD&D)

In 1e, only Wizards had access to 9th level spells. The spell lists for Clerics and druids went to 7th. Rangers and Paladins only had up to 3rd. Cantrips came out as a community suggested thing late in 1e, early in 2e, took a bit to become "official", and were still kinda tacked on, even then.

There were some non-official attempts at making spells of different levels (Dagon mag published one, a few companies put out some suggested versions that played with the spell layout), but nothing official.

Once WotC took over and published 3e, they might have done something, but I never saw it.

So, that's the rules.

Now, for Forgotten Realms Lore (that is, something that is not part of the game properly, but rather a history that is specific to  single world), their lore tells of a 12th level spell that let someone steal the power of a god.

But there has never been any spell over 9th level as a published as part of the rules.

(Side Note: I have lore that speaks of super powered spells in my game, too, lol, but they aren't something actually done. And I've rewritten the entire magic system several times. I have taken the existing spell list in the past and "stretched" it out over more levels, but again, that's not a standard game thing, and I haven't done that since 2004.)

Quote from Haravikk >>

Quote from AEDorsay >>

Or I might try to be pissy and point out that "we don't have all that many 9th level spells so why in the world would they try to introduce all of what, two 10th?"

I doubt we're going to see actual 10th-level spells, but upcasting beyond 9th doesn't really seem like a problem; most spells are at their best value at the level they start at, very few scale up well into higher level slots compared to what you could be using them for.

You don't see many people burning a 9th-level slot on healing word, as it's just not worth it for an extra 1-4 hit-points, in fact it's arguably not worth it to upcast it at all; just cast it at 1st-level when an ally goes down to get them back in the fight for a turn, then rinse and repeat when they go back down again. Not that a free 10th-level cast is terrible, free's free, as it's not competing with something else.

Even spells with 1d10 damage aren't all that amazing upcast; the main reason to upcast a damage spell is if the average damage at a lower level might leave enemies alive on a handful of hit-points, so you upcast a level or two to guarantee kills.

The more problematic upcast spells would be those that can have multiple targets, and even then I'm not sure it's all that broken really.

 
Oh, I know, I was being silly. Partially because folks have griped about there only being 9 spell levels as long as I have been playing, and that's 45 freaking years! Partially because it seems to be a habit of all the folks who have played forever to grouse about  "these young whipper snappers wrecking our game".

My group is super happy with the 0 to 9, ten step set up -- 10 levels is just fine for us. But we turned to spell points when 5e came out, and what we have and use now is so different from the core rules that it is only superficially similar.

I figured I'd point out that, with the UA9 healing word, the Sanctuary allows you to cast healing word at 10th level for 20d4 + spellcasting modifier points of healing.

Quote from AEDorsay >>

Quote from Mephista>>

Quote from AEDorsay>>

Well, imma be just plain old and say something like, i dunno, "well, when I was young, we didn't have these fancy things. There were only nine levels of spells, and only one group could use the highest two, and there was none of this flim flammery

Didn't spells go up to 12 in the old days?

 
Not in 1e/2e (AD&D)

In 1e, only Wizards had access to 9th level spells. The spell lists for Clerics and druids went to 7th. Rangers and Paladins only had up to 3rd. Cantrips came out as a community suggested thing late in 1e, early in 2e, took a bit to become "official", and were still kinda tacked on, even then.

There were some non-official attempts at making spells of different levels (Dagon mag published one, a few companies put out some suggested versions that played with the spell layout), but nothing official.

Once WotC took over and published 3e, they might have done something, but I never saw it.

So, that's the rules.

Now, for Forgotten Realms Lore (that is, something that is not part of the game properly, but rather a history that is specific to  single world), their lore tells of a 12th level spell that let someone steal the power of a god.

But there has never been any spell over 9th level as a published as part of the rules.

(Side Note: I have lore that speaks of super powered spells in my game, too, lol, but they aren't something actually done. And I've rewritten the entire magic system several times. I have taken the existing spell list in the past and "stretched" it out over more levels, but again, that's not a standard game thing, and I haven't done that since 2004.)

 Not entirely true.  Spell DID go to 12th level, PLAYER spells only went to 9.  It's a subtle difference, but it exists.  Karsus' Avatar was a 12th level spell, the highest I've ever heard of.  Tolodine's Killing Wind was 10th level, as were a couple of Weave Mythal spells.  Mavin's Worldweave was an example of an 11th level spell.  Those are from the TSR days in 2e.  They've never been player accessible spells, but they do exist.  They were republished IIRC in 3e as Epic Magic, and I don't know how accessible to users they were.

By canon, a player character playing in a timeline before the fall of Netheril /should/ have access to cast those spells, but the rules have never provided much detail on how they'd be handled as the game has always been designed to cap out at 9th level.

As far as the OP, I wouldn't read too much into that.  Players still don't have 10th level spell progression.  At best, this is a math rounding error and loophole that allows someone to cast a lower level spell at enhanced effectiveness.  I do not anticipate that they're going to mess up high level balance any further by adding a whole new level of spells.  High level play is only marginally supported as it is.  What's far more likely is them adding a statement that says something like "to a maximum of 9th level" and completely closing that math error.