Condition requiring an insured to take reasonable precautions to prevent accidents and safeguard property. The clause is not usually construed as a warranty, enabling the insurer to repudiate the liability irrespective of a causal connection between the breach and the loss (Lane v. Spratt (1970)). A liability policy is triggered by the insured’s negligence and so it would be repugnant to avoid liability because of the insured’s lack of care except, depending on the facts, where lack of care amounts to recklessness.