Is Tai Chi effective as a martial art?

Would you be able to easily defend yourself?

Log on to Youtube and type in "Combat Tai Chi".

If you want to defend yourself buy a machete.

You're safe, and its fun!
Yes, and it's very embarrassing for your attacker to get his a5s kicked in slow motion like that. Adds insult to injury quite effectively.
It's really an exercise and motion workout......
Traditional Tai Chi is actually an effective martial art. The movements that we are more familiar with, the stylized, relaxation type Tai-Chi, of course, wouldn't be of much utility to you in a self-defense situation, but in Asia (mostly), it is still being practiced as a martial art.
Hi!

I think Tai Chi is for self control - body and mind.
But you can adopt to self defense, just have to have some help, fantasy (how to use it). And practice a lot. :P
I learn kenjutsu, and we practice hand-to-hand combat too. It isn't that easy, to defend myself, as i thought for the first time. So technics, and practicing is necessary - especially for self defense. And of course, a partner, who learn self-defense technics, so he/she will know how to do it.
If you mean by "effective" quickly learned and with apparent combat uses, then no. Tai Chi masters who have put decades into their art are able to do Chin Na (joint locks and stuff) as well as any other style's master. But, let's say you're a 16 year old girl, and you want to learn a martial art by the time you get into college at 18 (years) and be able to defend yourself, (which I recommend for all women to study something in highschool, college is a dangerous place sometimes) I'd go with another style.