Destructible environment
Game worlds where walls, floors and buildings can actually be blown apart, rather than just swapping in a scorch-mark texture.
Red Faction sold its Geo-Mod technology in 2001 on the promise of blasting tunnels through rock. Battlefield: Bad Company in 2008 turned whole houses into cover that didn't last, on DICE's Frostbite engine, and Teardown in 2020 built everything from voxels so every plank can break. Between those sit most games, which prepare the fracture in advance: the model is already split into chunks, often by Voronoi fracture, and swapped for the pieces when something explodes.
The hard part is rarely the explosion itself but everything that assumed the world would stay put. The navmesh has to be rebuilt, baked lighting stops matching, and in multiplayer every client needs to see the same hole. That is why destruction is usually limited to selected walls, and why load-bearing stones turn out to be curiously indestructible.