It's easy to stay alive in H&H, and that's terrible. Let's make it more difficult with these Self Inflicted Challenges. If you beat them, then you gain the respect and yes, awe, of your friends and enemies*. Of course, there isn't really any "finish" to these, because the game is by nature open-ended. Thus, one can only really beat any of these by playing according to it's rule forever. You can, of course, give up a challenge at any time, but once you have you cannot start it again.
*And nothing else.
S.I.C.S.:
-Barbarian Diet: Eat only raw meat. ONLY raw meat. You are allowed to have beer with this, but not wine.
-Dwarven Diet: Booze. Both boozes, in fact. You may also eat mushrooms and Cave bulbs. Bonus points: When above ground, vomit.
-Barefoot Conquestador: Do not wear shoes.
-Vegetarian: Eat nothing but plants.
-Nudist: Wear nothing. Shoes are allowed.
-LEECH MAN: Wear a leech in every applicable slot. Bonus for regularly stating things like "I AM LEECHMAN; FEAR MY LEECHES!" and so forth.
-Mechanical Naturalist: Have full nature, but work at industrial tasks.
-Natural Mechanic: Have full industry, but only do nature tasks.
-Pets: At all times, have, in order of difficulty: a Frog/Rat; a Chicken or Rabbit; a fox, with you at all times. For the non-inventory animals, you'll have to arrange to be away from it for no longer than 20 minutes, ever. Unlike the other SICS, this one can be done many times simultaneously. Bonus points for one, three, or five additional pets. Note that these animals must be alive.
-Harmless Hermit: Starting with a new character, play with absolutely no kin/town, and without interacting with any other players at all. You may do this within the first three danger levels, however.
-Harmful Hermit: As above, but you may only raise your combat skills.
-Doomed Hermit: As Harmless, but you must not only start with a new character, but build your settlement at least one entire megagrid out, in level X territory.
-I like Repairing!: No house or other internal spaces in your camp.
-Caveman: Live in a cave, with only whatever you can't have in the cave visible.
-Amish: No worked metal, at all. You can't work it yourself, and you can't use anything made with it. In other words, like me but on purpose.
-The Spartan Way: You may invest no LP in any skill without immediate combat effect. You must similarly adjust your belief sliders. No steel, or shirts, naturally. For roleplay bonus, you can occasionally kill a "slave"- anyone who is not combat-specialized.
-Bear Grylls: Kill every bear you encounter. Bonus: Immediately after this, grill the meat.
-Les Stroud: Kill every bear you encounter, with no tools, no armor, and for a bonus, you must film it yourself.
Please feel free to add to the list, and make note of your accomplishments!
EDIT: added Leechman and Spartans.