What you would need to survive 3 days in the wild, or 2 days at home.

[Hud]

Basically involves Food, water, shelter and the means to prepare the food.
In the wild any season in North America.  You can add to this list, but you would be in trouble if the temperatures were below freezing, or extremely hot and you lacked one of the four components.

[Shootrj2003]

3 days? A big box of. Slim Jim’s, a pot to boil water maybe a couple cans of beer and  a sleeping bag and some semi sweet bakers choc. Some jerky too and tea or coffee and of course acouple knives 1 big heavy one and fire maker

[TrenchFoot]

full platypus and nalgene, a ceramic pump filter, wabonnet blackbird xlc, underquilt, sleeping bag, mountain house, pocket rocket, knife

[Amberjack]

If we're thinking minimalist gear, and I'm being picky...

Asbell Hooded Anorak
Gerber LMF aircrew knife (completely indestructible) (many other knives would work just as well)
Boiling pot
firesteel

3 days isn't long, eating is optional - staying warm and hydrated is not.

AJ