Lanza compares patent decisions to the game of chess. "You're trying to figure out what you're doing, what your competitor is doing, how to get around that, and whether, in the end, your invention still has value to the company."

Some inventions appear to be obvious, but in the nuanced realm of patent law, they're different enough to merit protection. Allstate was recently granted a family of three patents for customizable insurance, each of which covers related but different aspects of the invention.

Patenting a family of inventions protects you better than getting a single patent, says Lunt, who helps PARC formulate patent strategy. PARC works with clients such as Procter & Gamble and BASF to develop inventions that may be patented and also licenses patents to other companies. Owning a patent family, she says, "makes it harder for someone to peel out a piece of the technology and lock you out of some application of your idea."

Holding a patent means defending a patent, which can be expensive and distracting. The median cost to fight a typical patent infringement case in court is $2.5 million, according to the American Intellectual Property Law Association. The average time to trial is two to two-and-a-half years, the association says. Allstate, for one, is undeterred. In May, the company filed a lawsuit against Nationwide Mutual Insurance, accusing its rival of infringing on its first customizable insurance patent, granted a year ago. Nationwide's Vanishing Deductible offering, which decreases a customer's deductible for each year of accident-free driving, steps on optimization systems and methods Allstate owns, the suit says. When Allstate was granted two more patents in that family in July, the company added more infringement claims to the suit. Nationwide hasn't yet filed a response and continues to sell the Vanishing Deductible product. "We plan to vigorously defend our position," a Nationwide spokesman says.

One of the big factors in formulating patent strategy, says Adduci, is determining whether the competitive boost outweighs the burden. Adduci has considered seeking patents for recent software development work for an at Boston Scientific, a $7.6 billion medical device maker. The work, which he declines to detail, is innovative enough to patent, he speculates. But a patent would bring no payoff for Boston Scientific. "We're not a commercial software house, so I'm not going to bring it to market," he says. "We've thought about it, but honestly, the pain-gain ratio isn't there."