From DominionStrategy Wiki
|If your deck and discard pile are empty, gain 3 Golds.|
Windfall is an Event from Empires. It rewards you with three Golds for drawing your deck, and thus gives you incentive to build a slick engine first and then let this Event provide the payload once the engine is complete.
 Official FAQ
- If there are fewer than 3 Golds in the pile, just gain the remaining Golds.
 English versions
|If your deck and discard pile are empty, gain 3 Golds.||Empires||June 2016|
 Other language versions
 Secret History. It's a hard condition to meet so I felt like I could be just a little more generous.