Don't forget good old rubber bands. Generally greater range than stapples. Then there is always the ruler to the knuckles.:)
*Sigh* I trained interns in marksmanship with rubber bands. It's amazing what bad shooting habits they bring with them to work. Proper technique is apparently no longer taught in school.
Also, interns tend to flinch when getting shot at, which makes it difficult for them to fight duels. They have to develop proper focus so they don't miss their shot.
I've also had to teach the art of stealth, utilizing natural coverings such as filing cabinets, potted plants, water coolers, etc. as you advance towards your target. This is a most difficult art. Most assassins get shot once they get within range.