So many possible schools of thought on this.
Help me decide!
Underpants or trousers?
Underpants, trousers is zero, shorts is one plus board shorts.
Travelling light, 30l rucksack.
3 max, usually 2. Same rules apply to t-shirts.
One pair to ride in, one pair drying after being washed the night before.
3 is luxury.
3 pairs is luxury
Wear one, wash them. Wear 2nd pair whilst 1st pair dry. 3rd pair is handy when it's too wet for the washed pair to dry quickly.
Where are you going/what are you doing/how long for?
I took 5 pairs for a month in Nepal, take some travel washing fluid from trekmates etc that you can use in a sink. Then a trip to a laundrette after a couple of weeks.
Wow apparently I travel heavy! Certainly hasn't felt (nor smelled) like it at times!
3 - you can always buy more when backpacking.
I think an emergency pair is worth while if travelling in a developing country. 3 min here
More than I picked for my commute into work yesterday - so anything greater than none!
3 for me. That way you get a clean pair every day
Definitely no more than 2 - wear one wash one .
3 for me, and trowsers which provide protection from sunburn and insects. My backpacking trowsers are lighter than my board shorts.
Agreed about trousers! I just took a pair of crag hopper kiwis that could be zipped off into shorts (it helps if you don't give too much of a toss about looking cool)