If i win an auction on ebay, do i have to buy the item?

i'm tryin to find a good bike helmet :/

Yes you do. but..... no one is holding a gun to your head. if you win and don't pay, then you just get negative feedback, which makes you look bad and effects you in the future. Lets say you win and you found something better, its best to talk to the seller, and try to come to some sort of agreement. Sometimes their nice enough to just forget it, leave neutral feedback and relist or make you pay the cost of the initial relisting (no more then $3 on a normal, simple auction)

Did you somehow believe eBay was like one of those free poker websites or something? Other good questions to test your common sense:

1- If I jump off of a building, do I have to hit the pavement?

2- If I stick a pencil in my eye, will I go blind?

3- If I don't use the brakes in my car, will I crash into something?

if you win the auction and do not want to buy it you can send the seller a question asking him to keep the item and you do not want it just make sure they have not already shipped it

Yes . There is a chance that somone else may outbid you for an item.

Yes...its in the terms and conditions when you sign up. If you win an item on ebay you have to buy the item. Its their policy.