They're not pure SF rules, but can be used as such.
They're meant to simulate TV action shows from the Sixties and Seventies. Be aware, though, that a second edition is due out soon which changes the basic rules that have been around a fair bit.
Basically, the 7TV system works like this: You have a Cast comprising or 1 or 2 "stars" which are the most capable members of your side, a few "co-stars" and a bunch of expendable "extras". You equip them from a fairly generic set of weapons but each side has a Gadget Pool where you can purchase nifty cutting edge items.
Play is IGOUGO with initiative determined to see who goes first each turn. Then, each side can activate half their number of figures (the camera can only concentrate on a few bits of action at a time), which can be modified by any Leadership abilities your Cast has. Each model gets two actions a turn, choosing from Move, Shooting, Melee or a Special Action (disarm something, or operate a machine or whatever).
Movement is simple and is based in inches. With combat, you roll to hit and then you roll again, comparing the strength of the weapon being used to the defence value of the target.
Each Cast gets 2 event cards per game, which you can use at any time to influence the game in your favour. The game is very much story driven and is attempting to emulate your favourite old action TV drama. Your cast members will have Special Effects, which function as skills and abilities.
Like I said, a 2nd edition is on its way which seeks to reduce the number of counters used in the game and which handles the initiative and effects in a different way from 1st edition. I can't say which version is best, as I haven't yet played 2nd. What I can say is 1st edition is very good and well worth investing in. It's not a difficult game, but the tricky bit is remembering the SFX of your characters (you need character cards for all your forces): Often a character will have a good ability tucked away on the card which you'll overlook at your peril.
