Never screw with time travel. Also, never screw anyone while time-traveling. You could become your own Grandfather.

If you are a space marine, make sure you take off your helmet. If the audience can’t see your face, you’re a disposable extra.

All geneticists are inherently mad scientists. Kill them before they engineer some monster, or deadly virus, or virus that turns people into deadly monsters.

If a corporation is involved, they’re evil.

The cute alien is not. Cute things are not the basis of good movies.

If they ‘come in peace,’ shoot first. You wouldn’t trust a guy who introduced himself with the lines, “I’m not gonna kill you,” so why make an exception for ET?

Don’t put your global defenses in the hands of a sentient computer. It will get bored.

Grizzled marines survive. Clean-shaven pretty boys get their brains sucked out.

Always set phasers to kill.

Never tell anyone the odds.

They’re never the droids you’re looking