Depends on the person and situation.

if they're getting high when they need to be working effectively, then it is a problem. but if they like to light up after work with some friends, no problem with that.

It's not about how many times, but the habitual nature of the use. Just as in any substance abuse case.

The problem does not lie in how many or in how much...the problem lies in the behavior and why you wish to get high on any ongoing basis.

Once >=\

Zero tolerance policies everywhere bitches. We're going to bring the smack down down on ya'lls.

Just once. I'd say smoking one joint can trigger an addiction. Also, pot can be detected in your hair for years, so think about your future when you are confronted by drugs.

It could only be once. Sometimes you only need to try something 1 time to become either mentally or physically addicted to it. It becomes a problem when that person can no longer control themselves and NEEDS to get high instead of just having the desire to.

"I'd say smoking one joint can trigger an addiction. "

Hey man you obviously have never researched marijuana in your entire life if you're really going to post arguments like that. I've been smoking weed practically the whole summer and I haven't developed a noticeable tolerance for it at all. And I've been smoking more than just joints, I'm talking blunts and bowls. Today I smoked 2 whole blunts of pure weed and I have no craving or withdrawal symptoms. So before you go filling people minds with what you think is knowledge about that harmless plant, get your facts straight.