NEW YORK (MainStreet)  The game is on at MetLife stadium. Not between the Denver Broncos and the Seattle Seahawks, but a battle of billboards is being waged between marijuana legalization proponents and opponents.

Half a dozen billboards have been posted near the stadium with even more signs appearing throughout the New York/New Jersey area. The competing messages are the work of the pro-legalization Marijuana Policy Project (MPP) and the anti-grass Project SAM (Smart Approaches to Marijuana).

SAM's ad shows a football player with the caption "Motivation, Perseverance, Determination" with a marijuana leaf below the words "None of the Above." The ad reads, "Marijuana kills your drive. Don't lose in the game of life."

"Marijuana use saps motivation, perseverance, and determination,  the opposite of what it takes to win the Super Bowl," says SAM chairman and former Congressman Patrick J. Kennedy. "It is not a safe drug, especially for kids, and we need to reiterate the message to coaches, parents, players, and teens alike that it has no place in football."

In a recent television appearance Kennedy confounded like-minded marijuana opponents by proclaiming, "I agree with the president. Alcohol is more dangerous [than marijuana]." MPP Director of Communications Mason Tvert was quick to issue a rebuttal statement referencing the admission.

"If Mr. Kennedy is concerned about public health and safety, and he knows that marijuana is less harmful than alcohol, why does he prefer adults drink?" Tvert said. "Our society recognizes that adults should have the right to consume alcohol responsibly. Prohibiting those same adults from using a less harmful substance is not a very smart approach to marijuana."

MPP posted a spoof of the SAM billboard featuring a shot of tequila under the text, "Overdose Deaths, Violent Crimes, Serious Injuries," and a marijuana leaf under the text, "None of the Above." It also reads: "Prohibiting adults from making the safer choice is NOT a smart approach."

"The folks working to keep marijuana illegal appear to have run out of compelling arguments," said MPP's Tvert. "They are now just acknowledging that marijuana is less harmful than alcohol and telling people they will be losers if they make the safer choice."

The battling billboards began when MPP launched a series of billboards earlier this week surrounding MetLife Stadium that claimed the relative safety of marijuana compared to alcohol.

--Written by Hal M. Bundrick for MainStreet