(I won't cover the events sponsored by Microsoft recruiting held at colleges, because those are several steps more removed from the Seattle puzzling community than the intern ones, and even less visible to the average employee. Or at least they're the ones I know the least about.)
|Name||Link||Genre||Derived from||How often run||Length||Team size||Audience||Run by||Relation with MS|
|MS Puzzle Hunt||wikipedia||Conference room (non-linear, solve in a conference room, etc.)||MIT Mystery Hunt||Yearly-ish||24+ hours||12||MS employees (some non-employees allowed on team)||Whoever won the last one||On campus|
|MS Puzzle Safari||wikipedia||Conference room + stamp hunt*||MS Puzzle Hunt/letterboxing||Yearly, in the summer||6 hours||4||MS employees (some non-employees allowed on team)||Dedicated team||On campus|
|MS Intern Puzzleday||Conference room||MS Puzzle Hunt||Yearly, in the summer||8 hours||12||MS interns (some non-employees allowed on team)||Dedicated team||Sponsored by intern program|
|Non-Intern Puzzleday||my writeup||Conference room||Intern Puzzleday (rerun)||Once so far, presumably yearly a few months after Puzzleday||8 hours||6||MS employees, not interns (some non-employees allowed on team)||Same as Puzzleday||On campus|
|Intern Game||official site||Full Game (linear, in vans, with story, etc.)||Seattle Game||Yearly, in the summer||24+ hours||6-7ish||MS interns (no non-interns allowed)||Dedicated team||Sponsored by intern program|
|Iron Puzzler||Conference room + team-designed puzzles**||Bay Area Iron Puzzler||About every two years, in long gaps between Puzzlehunts||24+ hours||5-8||MS employees (some non-employees allowed on teams)||Whoever runs them||On campus|
|SNAP||officialish site||Mini Game (linear, on foot, etc.)||BANG||Whenever people run them, recently several/year||4-8 hours||4-6ish||Anyone||Whoever runs them||Independent|
|DASH||official site||Massively multicast Mini Game||BANG/SNAP||Every six months-year||4-8 hours||4-5||Anyone||Various teams at each site||Independent|
|Seattle Game||officialish site (dead link?)||Full Game||Early Bay Area Games||Whenever people run them, not since 2005||24+ hours||Anyone||Whoever runs them||Independent|
*When you solve a puzzle, you get a message that says "Go check out the pool table on X floor of Y building." So you go there, and there's a rubber stamp in one of the pockets or something, and you stamp a logbook you have to prove that you both solved the puzzle and found the stamp.
**The first half of the event has each team design a puzzle. The second half of the event has each team solve all the other team's puzzles; each team gets points for solving, solvability, and which puzzles are voted the most fun.