An internet language commonly used in online games. Goal is to replace as much letters with numbers and symbols as possible. 1337 being short for "elite"

The menial and unflattering, although sometimes fun, language of numbers and letters that began on internet games and forums, and has now somehow made its way into real life. "1337" is pronounced "leet", short for "elite."

the stupidest speak ever invented.....only nerds talk like that.

talking in a way that places numbers in the place of certian letters
1 = l or i
2 = R
3 = b
4 = A
5 = S
6 = G
7 = T
0 = O

1337- LEET- ELITE

To put it simply, someone who is the pwn (owns other people) or who thinks they are anyway.

Doesn't 1337 speak come from Counter-Strike 1.6?
Google 1337 Krew :)
From there we started using nub and n00b, and h4x and the language evolved...
You could often interchange characters for the same meaning:
7h475 6234t / th4t5 6r34t / thats great -- or n!nj4 / |\|1|\|j4 / n1nj4 -- you get it..