We wanted to keep combat to a limited zone of the exploration map.
That might sound counterintuitive to the core pillar where exploration and combat are connected in the same space, but actually we made this decision in order to further enhance that pillar.
Take a moment to imagine - You engage an enemy and enter combat. The enemy is a bit powerful, but relatively slow. So, you can outpace him. 'Let's run past him,' you might think to yourself. There may be more enemies waiting for you ahead, but what stops you from moving past them too? Or what if they're so far from the original fight that it wouldn't make sense to give them movement on the enemies turn (which could be solved through an aggro range tech but just stick with the imagination)? The player could essentially complete the entire area in combat instead of exploration. It'd feel a little clunky as every character has to be moved independently and player-enemy phases would need to play out as usual - and that's not quite the fun we had in mind.
So instead, we're strategically limiting the combat space. This ensures that play happens in both combat and exploration, keeping that core integration of the two as the main focus.
We came up with a few different ways to make the box, but we settled on the idea of the bounding space dynamically adjusting to the shape of the map. Essentially, the combat area "grows" from the point of engagement with the enemy. It grows into all adjacent passable tiles, and if the combat space reached an impassable terrain, it would stop growing in that specific direction. After growing a set number of tiles (which can be manipulated to make some areas feel more constricting), we've created a bounding box that fits to the explorable world while also ensuring experience in both styles of play.