If somebody owes you a large sum of money in rent and you have something of there's is it legal to sell it for the money owed??

No
BUT if they have no receipt or document they cannot prove it.

if you cant sell it can you pawn it and give them the ticket ,dont know if its legal but it sounds good to me but personaly i would just sell what you have

Only if they can be deemed to have abandoned said items, for example they left it in the property after moving out.

More: http://www.legalcentre.co.uk/tenancy-agreements/arts/abandonment-of-property/

Possession is 9/10ths of the law, innit!! Sell the stuff and be hanged!!

No. It would be classed as theft. You can't sell something you don't own.

The fact that the person that owns the item owes you money has nothing to do with it.

Bollocks mate, sell that shit, they can't do nowt about it.

does the value of the thing you have cover the full amount of the debt if so i personally wouldnt think twice of selling it to get my money back.but !!!!!!!!!!!

I thought he wanted a literal answer, not the immoral one that most people would choose.

If I owed you £2k or something and I went to see you and left the keys to my car at yours and walked home because I was drunked to death, would you take my car and sell it? It's a bit of an extreme example but hopefully it gets my point across.

No because a car has documentation.

Like I said, if he sells his crap and they run to the cops the cops will just tell them to take him to court as its nothing to do with them unless he has the receipt to proove ownership.
Thankya thankya.
What is it anyway?