In the law of contracts, an act of God may be interpreted as an implied defence under the rule of impossibility or impracticability. If so, the promise is discharged because of unforeseen occurrences, which were unavoidable and would result in insurmountable delay, expense, or other material breach.In the law of contracts, an act of God may be interpreted as an implied defence under the rule of impossibility or impracticability. If so, the promise is discharged because of unforeseen occurrences, which were unavoidable and would result in insurmountable delay, expense, or other material breach.
Dnt take literal meaning of the word 'Act of God". It simply means the act which is out of control of human being.and therefore any consequences which is uncontrollable by human being is 'Act of God'

Please add   "N" numbers of Shocking and Unbelivable judgments to the list"...

Act of god is an event or happening beyond human control. In case of such an occurrence no one can be held responsible or accountable for its causation. 
 
When an inevitable event hinders or causes or obstructs performance of any given contract despite reasonable care  such an inevitable event can be described as the act of god.

Act of god directly signifies the impossibility or impracticality. The parties are no more obliged to carry out their ends of the contract.

Caselaw

In Nichols vs. Marshland, A heavy rainfall occurred such as never witnessed in human history and made the water flow out of artificial lakes at the defendant’s place, ruining four bridges of the Plaintiff. The court here ruled in favour of the defendant stating that the rainfall was an act of god.

example: earthquake, tsunami or any such natural disaster.

However the term reasonable care is important as there might be situations wherein a certain disaster hindered the performance of a contract but such disaster could be averted by exercising reasonable care.

A judge ruled the flooding in New Orleans caused by Hurricane Katrina (an act of God) as an act of negligence, citing the US Army Corps did not properly maintain flood defenses.

The Origin

The phrase 'act of God' occurs in religious texts dating back to the 13th century, specifically referring to acts that God has undertaken. The 'act of God' referred to here is that which is used in legal and insurance circles when discussing any act which is outside human control and therefore not the responsibility of any individual or corporation. The term was first used in this way in the mid-19th century. Peter Simmonds' Dictionary of Trade Products, 1858, uses the term:

"Force-majeure, a French commercial term for unavoidable accidents in the transport of goods, from superior force, the act of God, etc.”

-Mahesh PS

-Law student