When exploring Lumiose City in Pokemon Legends: Z-A, you’ll often happen upon routes blocked due to things like rocks, heaps of poison, and overgrown thorn roots that you need to remove to reach some places or access items in Lumiose City. While you do need to wait a bit to get one move needed to break those rocks apart, the others can be eliminted right away with the right character or move.
How to break rocks in Pokemon Legends: Z-A
This is the one situation that requires a specific move, as it is tied to explaining Mable’s research tasks. You can break rocks and boulders in Pokemon Legends: Z-A by having a Pokemon that knows how to use Rock Smash summoned. Bring it out of your lineup. Bring up its move list. Make sure the character is targeting the rocks. Press the action button tied to that attack, and it will bust up the rock permanently. A good early character who can learn it is Bunnelby, though you can also teach some other characters like Riolu the move.

How to eliminate purple toxic poison in Pokemon Legends: Z-A
You don’t need a specific move or TM to get rid of those purple mounds blocking your way in some spots of the game. A water-based attack like Water Gun will do. Totodile learns this one really early on, so you could rely on that character to clean up Lumiose City in Pokemon Legends Z-A.
How to remove tree roots and thorns in Pokemon Legends: Z-A
When I first started playing Pokemon Legends: Z-A, I ignored the thorns blocking ways and hiding items for a while because I figured Cut would be used on those, before unexpectedly learning in a Wild Zone fight that a fire-based attack and burn roots up and remove them. Something like a Fletchling’s Ember will work just fine.
Pokemon Legends: Z-A is available for the Switch and Switch 2.