ALIBU, Calif. - One demonstrator was down on the ground. Another squared off against a police officer. Another and another and another locked arms, shouting and singing and swearing they would not budge.
In the background, 28-year-old Katie Flynn-Jambeck mentioned how much she was looking forward to teaching the protesters to scale buildings, once they had dusted themselves off and gotten a good night's sleep.
First, though, they had to finish playing cops and convention delegates at the camp run by the Berkeley-based Ruckus Society, a sort of graduate program for liberal protesters. Later they would master mass actions and learn that human blockades are no bluff. They were, after all, spending six nights sleeping in tents and sharing portable toilets, partly to confront their own fears, mostly to prepare to confront authority nonviolently at the coming Republican and Democratic conventions.
And they would have fun doing it. Anyone who wasn't could talk to the designated ''Care Bear.'' The camp was steeped in that kind of earnestness, with admonishments to recycle and tofu enchiladas served for lunch. Malachi Garza, a 21-year-old participant, good-naturedly described the crowd as ''medium to crunchy'' on the granola scale.
''We take our fun very seriously,'' said Ruckus Society spokesman Han Shan. ''If we can't do that, we can't take our populist movement to the world and have it catch on.''
Fine-tuned by the Ruckus Society, which has participated in nearly every major demonstration in recent years in the United States and many in Canada, the crowd of funsters expects to storm Philadelphia at the end of this month and Los Angeles next month with nonviolent actions.
The aim is to use everything from political theater to protesters locked together with tubing to convey concerns about the environment, human rights, corporate globalization, and a host of other national and international issues.
As John Sellers, the society's director, put it: ''We make an implicit political statement in deciding who we train. Our goal is to build a unified, sustainable democratic future, and that means pulling the power out of the hands of corporations.''
The camp, which is free and ends Wednesday, is the nonprofit Ruckus Society's 24th in five years. Nearly 100 people took part in a recent workshop on the East Coast. Another 150 or so representing 16 states are now broiling on borrowed land in the Santa Monica Mountains - one person out of every three or four who applied, Sellers said.
What they have in common is their relative youth, their commitment to political activism at a time when many eligible voters of all ages do not bother to cast a ballot, and their willingness to put their bodies on the front lines for their beliefs. That's what many said made them glad to give up the comforts of home or their paychecks to spend time at the rustic camp with spectacular views of the ocean and surrounding mountains, especially from the top of the scaffolding and platforms set up for practice climbs and descents.
''Climbing is more mental than physical because you've got to be focused on what you do,'' explained Flynn-Jambeck, who works in the development office at Hampshire College in Amherst when she's not suspending herself from bridges to stop factory trawlers from leaving port or unfurling banners above chemical pipelines to make points about environmental racism.
''You've got to stay calm, think ahead, and be ready for anything,'' she added. ''It's an ethic you should take with you into all direct actions.''
Many of the campers, herself included, were at last year's World Trade Organization meetings in Seattle. This year, they faced off against delegates to the International Monetary Fund meeting in Washington. In turn, they got hit with tear gas and pepper spray and shot with rubber bullets by police in full riot gear - even though, they insisted, they were not rioting and were only employing their legally guaranteed right to demonstrate nonviolently, even if it meant disrupting traffic or delaying delegate sessions.
Asked by a discussion facilitator how many of them had been arrested during protests, half of the group attending that session raised their hands. Questioned about how many were on probation, about half said they were, including facilitator Sarah Seeds. Terry Marshall, 23, who lives in Dorchester and works for the American Friends Service Committee, has not been arrested yet, but he said he is willing to be while in Philadelphia.
''We have the power and the right to demonstrate against injustices,'' Marshall said. ''We have the power and the right to put our bodies in the way of the machine. If it comes to [being arrested] I'll be arrested.''
But, as recent protests have proved, peaceful demonstrations are sometimes met with force - and one of the many exercises showed that more than a few of the campers would advocate violence under certain circumstances, if not by themselves then by others. So Ruckus Society leaders know they have to be ready for anything in Los Angeles, whose police department is facing its most widespread scandal in recent history, and Philadelphia, whose officers were recently captured on videotape beating a suspect.
That means practice ''hassle lines,'' where one-half of the group plays convention delegates, the other half demonstrators willing to say or do most anything except cause harm to keep the enemy from entering the convention hall. It means sessions on strategic planning and learning to listen one on one.
It means defining ''personal space'' and holding hours-long talks on imperialism and oppression. In this world of well-organized anarchy, it means melding high-tech techniques with old-fashioned grass-roots activism to hit home the points.
And the participants at the camp - sponsored by groups called the Action Resource Center, Global Exchange, and Youth Action for Global Justice Network - have scores of issues, many of them represented by T-shirts or hats made of hemp.
''Schools not jails,'' read one shirt. ''Defending Land and Life,'' read another. ''Resist the Global Oil Industry'' and ''Black Panthers Party'' also were represented. Even the volunteer kitchen staff had its own issue, reserving the right to sniff diners' hands to ensure they had washed beforehand to prevent the ''oral to fecal germ route.''
''Tyranny, tyranny,'' the crowd shouted in its first protest of the morning on the first day of camp.
''The types of messages you see here resonate with a lot of folks,'' said Mehrdad Azemun, a 28-year-old environmental activist from Chicago who is between jobs in his field and hopes to be outside the convention center in Los Angeles. ''But we're already interacting. We're hearing each other, and that's always good.''
Azemun said he came to the mountains to formalize his nonviolent protest skills. Jessy Fernandez, a 23-year-old Yale Law School student from Weston, Mass., said she relished the chance to learn among like-minded people while trying to improve the world. Doris Haddock, the 90-year-old grandmother who walked across the country to highlight campaign finance reform, said she had come to encourage America's youth to find political leaders who touch their hearts and to vote for ''none of the above'' for president until they do.
''Know when it's time to go,'' facilitator Sarah Seeds warned members of her group before sending them out to role-play again in the midday heat. ''Know when you've been co-opted. Know what to do when you get what you want because it happens so rarely.''
