adirobdack46r
What to bring depends on where you're going, weather, who you're with, and everyone's experience level. The growing consensus is that 4 is the minimum back-country group size.
Let's assume that you want to climb the ADK 46 in winter, with 3 friends of equal ability. After you've bagged half a dozen, you'll be able to tell me what to bring, but here's what I'd bring...
The essentials, on your person: map, compass, first-aid kit, knife, matches, and fire starter.
Clothing, three or four layers.
Head: Wool knit hat, fleece balaclava, wind-stopper face mask, goggles, sunglasses.
Hands: poly glove liner, fleece mitts, fleece gloves, windproof over gloves.
Body: poly long underwear, light wool sweater, fleece pullover, fleece jacket, wind/waterproof parka w/ attached hood.
Legs: poly long underwear, nylon hiking pants, wool pants, wind pants.
Feet: poly liner socks, smartwool socks (1pr spare), winter weight hiking boots, gaiters. In the Dak's, as a courtesy to skiers, snowshoes on any ski able trail
, trekking poles, crampons for above tree line.
Other personal stuff:
Easy access, outside, pack pockets: Trail food, 1L water in insulated Nalgene, whistle, LED headlamp, bandana, foam sitting-pad, camera.
Inside pack: 1L water wrapped in spare socks, 3000 cal of emergency food (cocoa, oatmeal, power bars, snickers), spare batteries (lithium), biner, chemical hand warmers, pen & paper, duct tape, TP, sun screen, lip balm, spoon, cup, plastic trash bag, emergency blanket, lighter, spare flashlight.
Stuff the group can share:
mirror, 50' paracord, 100' 9mm static line, altimeter, repair kit, leatherman, tent, snow stakes, ground cloth, 2 sleeping bags and pads, stove, 1pt fuel, wind screen, stove board, pot w/ lid and handle, candle lantern, snow shovel, group first-aid kit, GPS, radio, trail guide.
And the most important piece of equipment - your brain - your own good sense and experience. It's not just what you have in your pack, it's knowing how to use it with your gloves on, in the cold, wind, and dark; it’s knowing your abilities and staying within them.
I'm always asking myself "what if?" - what if it rains, what if it snows, what if we get lost, what if someone gets sick, what if it takes longer...
Choose your gear then try it out in the backyard on a cold night, then maybe intentionally spend a night out on the trail, practicing emergency procedures before you need them.
~Martin