Under rows of harsh fluorescent lights, they sit at folding tables, hunched over boards covered with small, square tiles.
The room is silent as 10 pairs of players sweat it out in a battle of wits, probing their minds for obscure words and letter combinations.
They're playing Scrabble, but this is not exactly the game that many people remember playing with their grandmothers over pound cake and iced tea on Sunday afternoons.
These are hard-core Scrabble players, many of whom also play chess, who enjoy the game for its challenge, discipline and mental stimulation.
And they take their games seriously, memorizing hundreds of obscure words and mastering strategies and lingo.
The Eagle Rock Scrabble Club was started in July by George Heussenstamm, a classical composer who teaches music composition and theory at Cal State Los Angeles and Cal State Northridge.
The club, one of more than 300 in the United States, meets from 7 to 10 p.m. the second and fourth Wednesday of the month in the Yosemite Senior Center.
Members pay $1 for admission, which covers Heussenstamm's mailings and the cookies and coffee provided at the meetings.
When Heussenstamm, a veteran Scrabble aficionado, started the club, there were only a handful of players.
Now the group averages 17, and he expects it to grow, following a national trend of increasing interest in the game, he said.
"It's something of an obsession," Heussenstamm said. "It's the kind of thing that once you start, it's hard to stop."
The club is an eclectic mix of people. At one table, a thin, dark man is listening through earphones to a portable tape player, moving his head slightly as his eyes flicker back and forth across his tiles.
His opponent is an unemployed Vietnam veteran who is also an avid chess player.
At another table, a 22-year-old physics major from Occidental College is battling a heavyset woman who is an administrator with the Los Angeles school district.
Scrabble clubs are highly organized and strictly follow a set of Scrabble rules promulgated by Scrabble Crossword Game Players Inc., a national organization.
Games are timed using chess clocks, and each player is allowed three minutes per move. And the players are serious about their games and strategies.
Like chess, Scrabble entails strategic planning.
Players learn rack management, a method of keeping a balance of vowels and consonants. Good players also have to know when to pass their turn, and how to work toward bingos--a move in which all seven letters are used in one turn. But the most important strategy is building vocabulary.
True Scrabble aficionados fervently study their Official Scrabble Players Dictionary.
They pore over lists of words, memorizing thousands of two- and three-letter words and their possible prefixes and suffixes to help them in their strategies.
Some of the word lists are so obscure that they almost look like random pages from a beginning Latin handbook.
Scrabble players learn such oddities as os, meaning orifice; ta, an expression of gratitude, and ho, an exclamation of surprise.
"The key is in knowing your words," Heussenstamm said. "You have to build a big vocabulary if you want to be good at this game. It involves more than just slapping letters on a board."
Someone bellows "challenge" from the far corner of the room, and Heussenstamm scurries away to settle the dispute.
Heussenstamm started the club in Eagle Rock because he wanted to be able to play in a group close to his La Crescenta home.
But as director, he has duties to fulfill.
If an even number of players show up, Heussenstamm doesn't play, and he must act as referee in the case of disputed words.
"It's been somewhat sacrificial for me," Heussenstamm said. "I don't get to play much any more."