the title says it all just looking for an answer lol =\
They could, but they’d probably need a lot of tidying up in another package first.
Sculptris, like most sculpting tools, produces models which have a massive number of polygons. This makes them look really good but makes them very slow to render in a game situation, and so not really suitable.
Generally the workflow is to make the high-poly version in the sculpting tool them use a conventional 3d tool (3ds, Maya, Modo, Blender…) to build a much lower polygon version, and then use the original high-poly version to create a normal map and to make all the other textures more realistic. This is a difficult process though and does require a lot of different skills, most tutorials for modelling characters for games will cover it nowadays.