Ditch Day is one of Caltech's oldest traditions—a cross between Animal House and a science fair. One day each spring, kept secret until the last minute, seniors ditch their classes and vanish from campus, leaving behind complex, imaginative scavenger hunts, mazes, puzzles, and other challenges that are carefully planned out to occupy the underclassmen—preventing them from wreaking havoc in the seniors' rooms.
Room Stacking 101
The original Ditch Day "stacks"— a Caltech euphemism for "locks"— were devices installed, or measures taken, by seniors to keep underclassmen out of their rooms when they were off campus for the day. (Stacking was also an extracurricular activity that could be undertaken any time, not just on Ditch Day.) Traditionally, there were three different kinds of stacks, each named for the approach required to undo it.
According to alumnus Chuck Lewis ('31), the first room stacking took place in 1931–32. In those days, "stacking" had quite a literal definition"— all the furniture was stacked in the center of the room in one tight configuration. As often happens in the English language, this definition expanded with time. It soon encompassed filling a room from floor to ceiling and wall to wall with neatly nested wooden boxes, crumpled-up newspaper, water balloons, even rebar-fortified cement. The type of effort needed to deconstruct such an arrangement caused it to be dubbed a Brute Force stack. More intellectual ways of securing seniors' rooms were soon employed as well. These required defeating sophisticated electronic, optical, chemical, or biological locks and puzzles, and became known as Finesse stacks. The third variety, honor stacks, left a senior's door unlocked, but underclassmen were honor-bound to solve a thorny problem before entering.
Stacks have continued to evolve over the decades"— most recently into complex puzzles that can combine elements of all three types. Because the seniors have to make good on any damages, Brute Force has fallen out of popularity. These days, stacks typically have themes inspired by books, video games, TV shows, or movies, and underclassmen team up to solve them. These teams are typically identifiable by T-shirts (or hats, or sometimes complete costumes) bearing the name of the stack they're attempting to solve.
Room stacking may no longer be all about broken concrete, stacks of wood, and jackhammers, but like the rest of the world, it's become firmly entrenched in the digital age.
