Well, I view the process of re-evaluating what you carry as something that should NEVER stop. You always add, remove or change items to adapt to changes in season, environment, fitness and travel companions. At least I do, and I don't have any plans of stopping anytime soon.

The question you ask is a valid one, but do you notice how the answers you're getting are essentially variations of the theme: Figure out what works for YOU! That is because no one can make that decision for you, nor can we know all the specifics about your situation necessary to make that decision.

That does not exclude a meaningful debate of the balance. Personally I carry very little in terms of redundancy. I'll list them here:

Fire: Lighter + some sparking implement (sparklite or fire steel). Some PJ cotton balls are backup for natural tinder.

Shelter: A combined tarp/bivy bag/poncho thingy + plastic poncho + garbage bag (not all of these all the time). If I actually plan on sleeping outside I will bring tent/tarp and a sleeping bag. Now the tricky part: The level of redundancy depends on my planned activities. If I will leave the tent for short hikes I will bring some minimum backup emergency shelter that will go along for the short hikes. If I will either carry or be with my tent at all times I may say "to heck with 0.6 kg of bivy bag, I have a friggin tent (also an excellent bivy bag, BTW - don't panic if you can't pitch it) and if I feel particular paranoid that my tent may blow away I'll just bring some big trash/garden leaf bags".

Flashlights - but that's just because I'm addicted to shiny things. Otherwise, it would be scrutinized according to Benjamin's decision check list.

Knife will sometimes be backed by multitool (mission dependent).


Some of the points made in the "backpacking light - deodorant..." thread are highly relevant to this discussion. Ultra light backpacking is an exercise in the art of minimizing to the extreme, with close to zero redundancy. There's a lot to be learned from the ultra light backpackers, but we don't need to embrace their philosophy to the fullest.

In summary, I will say that redundancy makes sense
a) for some very critical items (but very few!) Fire, shelter, water. And you seek redundancy in function, not duplicate items.

b) If separation from your main gear is likely. (Such as wandering off from your camp on a supposedly short hike, or being tossed out of your canoe).

Edit: This is from a wilderness trip perspective. For EDC, Benjamins thoughts are highly relevant.