Boxers are not good guard dogs. They are not vicious despite their high energy and sturdy physical appearance. They are playful, family-oriented dogs that need constant attention from their owners and are difficult to train for attack. They are very affectionate.
Boxers make better watchdogs than guard dogs. They are suspicious of strangers and can alert their owners to the presence of intruders. However, they rarely do more than bark. In fact, some boxers are friendly to everyone including strangers. Boxers are often trained to be guard dogs although they are not suited for it. They were used in both World Wars as guard dogs, messenger dogs and ambulance scouts.