I bought Tasha's Cauldron of Everything last month and have enjoyed it thoroughly. My question has to deal with the "Changing Your Subclass" rules found on page 8.
The first paragraph under that section heading says that characters can change their subclass when they would normally gain a new subclass feature.
The next subsection, "Training Time", goes on about how changing a subclass might take time, money, and/or a quest. How does this work with the previous paragraph's rule of only changing subclasses when a character gains a new subclass feature? For example, if the character needs time to train or complete a quest, I'm not sure how you could align that with gaining a new subclass feature.
The final subsection, "Sudden Change" says characters could have an immediate subclass change. Does this mean immediately when a character would gain a new subclass feature, or at any time at all?
These three sections almost seem like different rules altogether for changing subclasses. I get that the two subsections, "Training Time" and "Sudden Change", shouldn't be mixed. However, the rule about only changing a subclass when gaining a new subclass feature is under the main section heading. This makes me believe this rule should be applied to both of the subsections. If not, then I feel like this should have been its own separate subsection as well.
How exactly do the rules on changing your subclass from Tasha's Cauldron of Everything work? How do they interact with one another (or not)?
I'm fully aware that these are optional rules and that D&D generally has just guidelines. I've been DMing for a number of years now and have that understanding. However, I'm looking for a more rules-based interpretation. Saying that these could be used in any fashion I like doesn't really help me.
Best Answer
"The DM might..."
These are not rules in the traditional sense. These are suggestions a DM might use to facilitate a subclass change in their game. Under "Training Time", we see (emphasis mine):
And under "Sudden Change", we see (emphasis mine):
These are not rules. These are suggestions to help a DM facilitate a subclass change, which is a pretty significant change. The idea here is to make the transition just as meaningful as where you came from and where you're going.
How would I personally work a subclass change?
I would ditch the limitation of "you can change your subclass when you would normally gain a new subclass feature."
The two methods offered give us distinct approaches for handling two different situations:
In either situation, I would work the subclass change at their next level up. In the first scenario, if they give me time to work in some plot, there is going to be some significant plot leading up to their next level up that will culminate in a change of subclass when they finally level up.
The second scenario is when I would use the "Sudden Change" guidance. If we are nearing a level up, and my player says "I want to change subclasses", I don't have time to work in significant plot build-up to the change, so I will opt for something like is suggested in this section at the next level up.
In either case, I am looking forward to the next level up, not the next subclass feature.
Waiting for a level up is how I would first express this to the player. If they felt that was too long to wait, I would of course see how we could work a transition even sooner.
What about rogues?
I present rogues as a use case for why I would break from the guidance given in the book. Rogue subclasses have a huge gap in features. Once a rogue gets their first subclass features at 3rd level, they don't get another until 9th level.
Say one of my players is a 5th level rogue and wants to change subclasses. I'm not waiting till 9th level to allow this. In this case, I would ignore the suggestion given in Tasha's Cauldron of Everything and still work the subclass change for their next level up.