I would like to print LEGO compatible figures. Which resolution is required for the 3D print in order to firmly fix the figures on LEGO bricks?
Depends on your tolerance. :)
http://en.wikipedia.org/wiki/Lego says: "The machines that make Lego bricks have tolerances as small as 10 micrometres."
For me, 3D printing resolution would need to be pretty close to that.