How does a 'bidding war' work when buying a property in Ontario?

In a Seller's market (more buyers than properties available to purchase) there can come a time when more than one offer is given for a property, and there becomes competition between buyers. This can result in what is called a 'bidding war' for the property. Don't confuse this with a real estate auction (which are rare in Ontario) 
 A Bidding War doesn't always happen, but is more likely on a well-priced attractive property in a good location AND usually results in more money for the Seller, and multiple disappointed Buyers who were not successful in their 'bid'. This is the hope for Sellers and the dread of most Buyers. Each bid is a proper, signed offer submitted to the Buyer's agent by each Seller's agent. At a set time the Seller's will review the offers and choose the successful offer. This can be done in one, two or more stages, depending on how many offers there are, and the preferences of the Seller. If the Seller's agent represents a Buyer and has one or more of their own offers, they need to disclose this to all all other Buyers who have an offer. Sometimes the Seller's agent will intentionally avoid working with a Buyer or ask a colleague to handle that client so there is less likelihood of conflict-of-interest when there are multiple offers (bidding war scenario)
Note: you should talk to your agent when listing your property, and ask them how they will handle multiple offers, or a 'bidding war'. If you are working with a Buyer's agent ask them how they approach a 'bidding war' with their clients.