How would you make turn based battles more engaging? (Aside from the mechanics that the mario and luigi and paper mario series use?)
In my current opinion the key is to have a much wider separation between optimal decisions and suboptimal or terrible decisions and to have these change on a turn-by turn basis. To really make Turn Based Battles more engaging, you need to make it more about the player evaluating the circumstance and needing to judge what options are best for the situation. These need to change turn by turn so that the player rethinks on a continual basis, so they are engaged in the primary challenge.
How do you do this? First, options need to have tradeoffs versus other options. If you have a clear sorting order, like a bunch of JRPGs that have Bolt1 Bolt2 Bolt3 or something along those lines, you end up with people using the most powerful option most of the time. There need to be other variables and dimensions to options besides how much HP damage they output in order to make them worthwhile over your most damaging option. In SMT, attacks that hit opponent’s weaknesses also gain turns for you, turns are another dimension of advantage that can ultimately translate into more damage than simply your most damaging option at that moment. (though obviously the problem here is that hitting their weakness usually is your most damaging option, then you gain a turn on top of that, so not the best example).
Ultimately what determines who wins in a turn based RPG is who can output the most damage, so everything comes down to either doing the most damage every turn, or setting up a circumstance in the future where you can output even more damage than you are now, while also balancing these against your survival. So the most basic tradeoff is dealing damage versus healing it, then dealing a lot of damage now versus more later, versus healing. Most traditional stat buffs in JRPGs are basically things that allow you to deal more damage in one way or another. You get direct damage buffs, which increase your damage on later turns, speed buffs which mean you attack faster, dealing damage more frequently, ultimately dealing more damage, accuracy buffs, which mean missing less which is more damage, etc.
So the questions to ask are, how can I make an option tempting that isn’t one of these existing options without making that option the only one people want to pick? How can I make people want to pick a different option every turn? How can I make someone want to prioritize different targets every turn? What other resources besides enemy HP and own HP can we make the player compete with enemies over?
Some basic ways of doing this are decay cycles, having things drop off in effectiveness over time, like how buffs in SMT expire after 3 turns, so they need to not only have a turn spent on applying them, but also need to be reapplied periodically, which can eat out of damage output in the short term. The Breath of Death VII and Cthulhu Saves the World games have enemy power grow by 10% every turn to stress efficiency, so if you can’t take out enemies fast enough, you will end up with enemies that can annihilate you, so long term setup strategies are not always as good as getting in that blast of damage to eliminate an enemy damage source this turn.
Other ideas are having things become good and bad on cycles, then making sure the options have orthagonal benefits to each of them so they’re tempting even during cycles where they’re bad over the options which are good that cycle. I’ve never seen this one done before.
Enemies can be spread out and attacks can have different hit areas so that you might be forced to hit certain enemies along with other enemies, and not get the optimal effect where you want it to. So like you might hit the weak to fire enemy with the brunt of your blast, but also the absorb fire enemy gets the second most intense part of the damage splash, healing it, so you might have done a really big net damage to the enemy group, but still healed that one pesky fire absorbing enemy. one ability might only affect every other member of a group, two enemies might be adjacent and needed to be killed on the same turn to die, so you can’t use that ability to kill them, but you can use it to hurt the one that’s ahead in life so they’re within range of each other.
It’s all about coming up with tradeoffs like that, and enemies that play off those tradeoffs.
I kind of like this question because it demonstrates a real predictive quality of game design theory in an area that is very abstract conceptually. I can talk about what the potential answers to this question would look like even without giving specific answers.