Aopy said:
I need to know how much a backpack can hold, a sack, saddle bags, etc.
I do not know about D&D backpack, but from real life experience, assume a 1 cubic foot inner capacity for a light back pack, and 2-2 1/2 cubic feet for a heavy one.
2 cubic feet of gold pieces weigh over a ton (2000+ lbs) !
2 cubic feet of water around 125 lbs, still an awesome load.
Assuming a balanced equipment (somme metal stuff, but mostly food, clothes, bedrolls…) I would allow a 30 to 40 lbs per cubic foot average.
Meaning :
• light backpack : 40 lbs max load, more likely 25-30 lbs.
• heavy (regular adventurer) backpack : 100 lbs max load, more likely 60-75 lbs
+ some stuff strapped on/hanging around the backpack.
The fabric probably won't stand much more anyway.
Hope this helps.