Nothing if not regular
Just in case anyone was in any doubt whatsoever that Planescape could very well be a thing, this subclass for Sorcerer takes us (or your Sorcerer's soul at least) to Mechanus, the plane of ultimate order, Modrons, cold, unfeeling logic and that moment when your alarm rings at 7 o'clock on a Saturday morning to punish you for not getting enough sleep the night before.
The flavour text for this subclass is wonderfully sinister - “you might have become entangled in one of the machinations of the leader of the Modrons.” No, they're not an 80s band... although maybe they should have been! Such entanglement has ignited your ability to fling spells in an entirely rational and pre-programmed way. You are the polar opposite of the Wild Magic Sorcerer!
To round off the flavour section, you get a table you can select from or roll on... if you so choose, to illustrate what happens to you when you cast spells. This approach is great – it means that you as a player get to decide whether or not you want to engage with these particular effects, or if you want to manifest your connection to Mechanus and clockwork in another way, such as through your costume design or by playing as a Warforged!
Each of the features below includes a summarised reference to the rules in the Unearthed Arcana article but it's worth downloading the full, free PDF from the Wizards D&D site, here.
Clockwork Magic - 1st Level
Learn new spells for free at 1st, 3rd, 5th, 7th and 9th level.
This extended spell list is a big deal for Sorcerers – one frequent complaint about the class is the limited number of spells that they're able to learn. Having a table of freebies that you don't have to spend your resources on is an immediate solution to that problem, and some of the spells that you get here (notably Counterspell) really makes this an impactful feature... to the point where it blows other Sorcerer 1st level features right out of the water, and does leave me wondering whether or not this is an indicator we'll be seeing 5.5e after all.
Divine Soul Sorcerer and Shadow Sorcerer both see you picking up an extra spell from your 1st Level feature, and Divine Soul's also incorporates a way to tamper with fate into the 1st level package (as does this, see next entry). This gives you... 10 spells instead of 1? I love it, and the flavour of the selection of spells that have been chosen, but this seems quite unfair compared to what other Sorcerer subclasses have to offer.
Restore Balance - 1st Level
Use your reaction to cancel advantage or disadvantage for a creature within 60 feet. Use a number of times equal to your Charisma modifier per long rest.
Again, this is super flavourful. “Thought you had advantage? NOPE! Your advantage didn't make sense and it lost a logical argument against my ban hammer.” It fits in nicely with other Sorcerer subclasses' fate-tampering powers, too (e.g. Divine Soul, Wild Magic), and can be very useful against enemies with pack tactics – especially if you're looking after your squishy caster character and keeping them on the fringes of the fight instead of right in the middle of it!
Bulwark of Law - 6th Level
Spend up to 5 sorcery points. Each creates a d8 that can be rolled to subtract from damage taken by your choice of target – you or a friendly creature within 30 feet.
And, just like that, you do get to wade into the thick of things. Failing that, you can try your hand at a bit of damage mitigation if your party has a tank or someone who loves to throw themselves head first into trouble.
This gives Sorcerers an option to play in a similar style to an Abjuration Wizard, and it's the start of this subclass proving itself to be something new and unique – and this is yet another example of this round of Unearthed Arcana continuing to breathe fresh air into classes!
Trance of Order - 14th Level
Use a bonus action to cancel any advantage on attacks against you for 1 minute. For that minute, any of your ability checks, saving throws or attack rolls that roll 9 or less count as 10 on the dice.
I can't say I've heard of the concept of clockwork consciousness before (sounds like some kind of self help scheme) but nonetheless this is another step towards Sorcerer tanking. Combine this with some of the Sorcerer features from the massive list of optional class feature upgrades and replacements from the end of last year, and you're looking at a character that can shield themself, convert a resource into large amounts of temporary hit points - and opponents can't easily take advantage of ganging up against them! Suddenly, that d6 Hit Die and lack of armour proficiency don't set you back so far – other Sorcerers may be tough, but this might just give you the edge!
We also see an added chance to use this an additional time before you rest if you're willing to fork out 5 sorcery points for the privilege. This provides much more flexibility than some of the other subclasses tend to see, and really lets you toughen yourself up in a pinch – and that's before we even mention your boosted chances of succeeding in all 3 of the types of check you can be called on to make!
Clockwork Cavalcade - 18th Level
As an action, create a 100ft cube in which every broken item is repaired, you can heal a combined total of 100HP across all friendly characters inside its boundary, and you can choose to end every spell of 6th level or higher on any creatures within it.
In terms of imagining how this would look (the descriptive text paints a picture of intangible Modrons hurrying around in the cube, fixing everything they can get their hands on), this is one of my favourite subclass capstones. This ability is great for helping your party out of a tough spot – being able to heal such a large chunk of HP across your party will never be a bad thing. Imagine if you are attempting to be the sorcerer tank, though – being able to just pop a 100HP heal out of nowhere is amazing! For comparison purposes, this is on par with a Paladin's 20th level Lay On Hands. Popping a 100-point heal will keep you going for at least a few more hits, and the fact that you can re-trigger this effect before you take a long rest gives you peace of mind that you're likely to survive the upcoming turmoil.
The flavour for this subclass is very strong, and the features that go along with it are the perfect way to enhance and deliver it. The impact it's likely to have on the Sorcerer play style is significant too. While healer sorcerers can already exist thanks to the Divine Soul subclass, this brings a new dimension to that concept, allowing you to serve as a healer at higher levels without having to worry too much about spell slots. On top of that, the self healing potential here is a real thing, which is something that really does open up possibilities for playing the Sorcerer in different ways. Some would say that's perfect, and exactly what Unearthed Arcana is meant to do, and I would be one of them... but with that said, I still can't help but wonder whether the extended spell list from level 1 is maybe a bit too overpowered when compared to other subclasses... let's hope that Wizards clock that (groan) and take a second look at whether it grants Clockwork Soul a large or minute advantage over the other choices of Sorcerous Origin. (Double and triple groan).