The Washington Capitals play the most important game in their three-year history tonight, carrying playoff aspirations into the Los Angeles Forum against the Kings.

Los Angeles holds third place in the Norris Division, six points ahead of Washington, and only three teams in the division will earn the right to play for the Stanley Cup in April and May.

"I try and get myself up for an intrasquad game," said Washington coach Tom McVie, "and I'm not going to treat this game any differently. But in terms of results, it is more important than anything we've done."

"It's the biggest game of the year," said center Gerry Meehan, who has recorded 10 points during the Capitals' unprecedented four-game unbeaten streak and was named NHL player of the week on Monday. "If we win, it's four points. If we lose, it's eight, and eight points with so few games left (27) would make it awfully tough."

"We can't rely on somebody else knocking off L.A." siad goaltender Bernie Wolfe, a frequent hero during the club's first .500 month, that ownderful 6-6-4 January. "We have to do it ourselves. If we go for points in every game and don't concede anything to anybody, we'll get to the playoffs."

The Capitals will unleash a secret weapon in the big battle.Winger Craig Patrick, signed yesterday after clearance from the World Hockey Association, will be in the lineup. Patrick became a free agent after the Minnesota Fighting Saints passed into martyrdom.

"Patrick was Minnesota's best player for a while, but then he got hurt," said general manager Max McNab. "That was a break for us, because when it came to picking up the players, his statistics weren't impressive and they passed on him. I've always liked him. I talked to him last summer, when he was a free agent, but we had so many contracts."

Patrick, born in Detroit, is a University of Denver product. Now 30, he has NHL experience with California, St. Louis and Kansas City. He seems destined to replace struggling Tony White at left wing on the Capitals' checking line with Ron Lalonde and Bill Collins.

The Capitals have never won in the Forum, dropping seven previous decisions by a combined score of 34-10. In their first Coast trip this season, they were humiliated, 7-1. Two Capital Centre meetings resulted in a 5-5 tie and a 4-2 success for the Kings.

"What's happened before doesn't concern me one bit," McVie said. "They're going good again (the Kings have won four of their last five), but our hockey club is capable of going to L.A. and winning under any circumstances. Before, we had to be at our best and they had to play an ordinary game. We still can't let up, but we are capable of beating them at their best."

McVie and McNab conducted a joint search for practice ice yesterday, with McVie insisting that "if the only ice available is at 10 p.m., we're on." However, McNab finally tracked down an old friend at the Culver City Ice Rink near Los Angeles and arranged a 3:30 (PST) practice session.

McVie claimed his desire to get the team right to work after yesterday's morning flight had nothing to do with the celebrated jet lag that supposedly affects teams heading west.

The Kings have been more vulnerable at home than usual this season, posting a 10-10-4 mark that just about matches the Capitals' 10-10-6 record at Capital Centre. CAPTION: Picture, New York Ranger goalie Gilles Gratton shows off his newly acquired face mask, purchsed for $300. UPI