Assuming we get an iterative sequel to TTYD, how would you like or how do you predict the battle system to be expanded or changed, if at all?
I agree that the way Tattle works is not ideal, but I'm not sure what solution I'd like exactly. Something that doesn't lock you so heavily to one character.
As for bold new concepts, I don't know how well it would work, but I'd be really curious to see what adapting Paper Mario's combat to Ikenfell's 3x12 grid would look like. The game has a much simpler battle system more comparable to Mario & Luigi, but the positioning adds another layer of strategy where every attack has a very particular range of squares it can hit relative to the user, and so the thing that really struck me about that was how it avoided repetitive encounters against the same enemies by requiring you to move differently every time and react accordingly. No two fights are the same, every single one is engaging.
I also think there needs to be a reckoning with RNG mechanics in some way. What makes Paper Mario unique from pretty much every other RPG is being almost completely devoid of chance. There are normally no percentage-based attacks, no crits and misses, no damage ranges. Everything is done with small, entirely predictable numbers, which makes it a very different experience from a highly reactive game like Dragon Quest. The only major factor of RNG in the original game is what attacks an enemy uses I think, in situations where they have more than one. But the fringes of TTYD introduce a lot of systems that are much more random, and these tend to be the weakest links. The worst partner attacks in the game are ones that take the form of fairly standard RPG abilities, with a chance to apply some status effect to enemies. The problem is, this is Paper Mario. You have to spend from your one very limited pool of FP, use one of only two turns you get per round, and execute an action command, for a
chance at this move to apply a status effect that has a
chance of preventing the enemy from attacking you the next turn.
The biggest one is probably the stage effects. They introduce the sort of chaos standard to other RPGs, but here it just comes off as the game randomly fucking you over or winning the fight for you because it's at odds with the level of precision the combat is otherwise built around. One point of damage or a single turn in which you cannot attack is a lot more meaningful here than it would be in other games, and it doesn't help that these things can occur in any context.
What I think the brilliant thing about TTYD's battle system is, by the way, is how it allows success to come from different avenues. This idea is at the core of the combat, even from the first game. On a basic level, you cannot succeed without a mix of both strategy and execution; your attacks will be entirely ineffective. This is what the jump/hammer dichotomy, the partner and badge systems, and the action commands are all about. The latter is the execution element, but the former create the formula of Paper Mario's strategy. Badges and swapping partners can change what moves are at your disposal, and it's up to you to solve the puzzle and identify the most efficient moves for dealing with whatever group of enemies you encounter.
TTYD adds many more additional complications into the mix. Like,
many more. What makes this overcomplicated pileup of systems sing though is the increased ability to shore up a lack of knowledge in one area with another. I wasn't great at action commands, so I needed HP and defense more than a master at them would. I didn't use items much, but I made frequent use of Sweet Treat and Earth Tremor, providing me with the same healing and powerful AOE effects through a different avenue. Similarly, I never used Power Lift, but I was instead able to boost my attack and defense using badges.
This gets the game accused of being easy, which it maybe is a little bit, but I think it's also important to take into account the sheer complexity of the battle system as its own challenge. An expert with no restrictions can trample over the game in many different ways, but that isn't trivial to do, and it's by design that you simply don't need every system in this game because using them isn't free. Badges have to be obtained and require BP investment and devising a strategy around them for the truly broken ones. Items cost money, shops are not always at hand, and your inventory is very limited. If you want to heavily rely on special moves, you need to master their complicated inputs and work out a way of supporting your star power use through related systems, or they'll be ineffective and rarely usable. Being really good at action commands lets you put less emphasis on many other systems because they're a straightforward way of increasing your damage output and reducing the damage you take, albeit incredibly difficult to master. (On that note, I wonder if an all-or-nothing attack counterpart to the superguard would work...)
Perhaps its weakest point is that you can get through the game while only knowing a little bit here and there, which is the context in which the combat is at its least interesting. This is why I question if the level up choice of HP/FP/BP should exist at all, because especially in the first game where you have fewer alternatives, choosing anything other than BP simply makes for slower gameplay where you use raw numbers to win through attrition rather than really engaging with what the systems have to offer. The thought I had was to make badges the clear main focus of the battle system and possibly relegate upgrades to HP and FP to overworld exploration ala what the later games did I believe?
Also it could definitely use a built-in hard mode that isn't afraid to push the battle system to its limits, because most of TTYD is perfectly doable without engaging with it too much, except for the difficulty spikes at the end of the Palace of Shadows and the Pit of 100 Trials. The former of which is particularly awkward. I assume that "you can get through the game while only knowing a little bit here and there" notion was intentional since the game doesn't give you any advice on how to use most of its mechanics practically, and some concepts like the different behavior of the audience member types go entirely unmentioned. It's a strange situation where the vast majority of the game's combat systems are more like a bonus for the ancillary audience to figure out for themselves, while kids are expected to just stick to the basics (and then get fucking destroyed by the boss rush at the end).