: : How close do you have to be to a black hole before you get sucked in?

: At the event horizon (which depends on the mass of the black hole), you will get sucked in. Outside, you have a chance to get away, if you have a powerful enough rocket engine.

Also, a black hole will have gravitational effects beyond the event horizon that will effectively 'tug' an object toward it. The intensity of the gravitational effect is related to mass. Also, depending on the mass of the black hole, an object can experience extreme tidal forces that rip an object apart long before reaching the event horizon.