As of March 2013, the way that patents are granted in the U.S. has undergone a radical change.

For more than 200 years, when two or more people claimed to have invented something, the key question was who actually invented it first. Starting now, however, the key question will be who was the first to file a patent application. This means that the second person to invent something might nevertheless “win” the patent simply by winning the race to the U.S. Patent Office.

This change is part of a new law called the America Invents Act. This law also makes very big changes in the process by which someone can legally challenge the validity of someone else’s patent.

If you’re interested in obtaining a patent, there is now much more of a premium than before in acting quickly, before someone else gets the same idea.