I found this quote in forums:
Marsh wrote:The only thing our license agreement says is you can't make money off of it. Other then that you are welcome to use all our assets for whatever you like.
now suppose there is a commercial game that depends on torchlight assets. game distribution would not contain any of those assets, and in order to play that game user first would be required to purchase and install torchlight. question is - would such scenario breach torchlight license?
to my thinking it should be perfectly legal, as developer of such game would be monetizing only his work (game binaries), and torchlight team would get more revenue because of required depency. OpenMW do such thing with morrowind resources (except they do not monetize game).