1. A plan that is uncomplicated and easy to understand.
2. An incredibly complicated plan in disguise, generally cooked up by someone with too much time on their hands, and usually involving at least 3(x+y)/6+x(3.356(x-y)) steps than necessary, where y equals the actual number of steps necessary, and x equals how much time was wasted in concocting it, multiplied by the GPA of the creator. Squared.
3. A variant of both Definition 1 or 2, unique in that it will never, ever, EVER work. EVER.
1. "Look, it's a simple plan: In the event of a volcanic eruption, get the hell out of town."
2. "It's a very simple plan, really: In the event of a volcanic eruption, first build a spaceship out of pixie stix, but only the strawberry kind. Then fly it up into space and shoot a pixie stix laser down into the volcano's northwestern side, at precisely a 32 degree angle. Then land back where you started, proceed east by southeast at approximately 1 1/2 miles per hour, skipping every seventeenth step, except on the 289nth step, when you must HOP. Repeat, HOP. By this point you should be within fifteen thousand miles of the volcano. Congratulations, you will now be safe."
3. "In the event of a volcanic eruption, all you need is one simple plan: Duck and Cover. That's right, Duck. And cover. All you need to do is duck and cover."