I just bought a Honda Civic with a manual transmission and when its in gear the shifter knob has alot of play and moves alot from side to side what would cause this?
the "knob" has a lot of play or the whole shifter assembly? Are the gears easy to find and defined well? If so, there are no problems. If you are use to driving a rear drive manual transmission car (miata, etc.), then a front wheel drive shifter is never going to feel as good.
Well the Civic should have two rubber bushings that go between the lower arm of the shifter and the linkage for the transmission. You probably need to replace those bushings, they go bad after a while and can allow a lot of play.
edit: Found this, might help you out!
http://www.automotiveforums.com/t741025-sloppy_shifter_in_5_speed_civic___alot_of_side_to_side_play_when_in_gear__bushings__guides_.html