Leetspeak or |33t5p34k is a form of heavily modified English, meant to be Elite Speak. It is used primarily on the Internet and the main difference with normal English is that it uses various ASCII characters to replace latin characters, making it a form of substitution cipher, and many variants of it exist across Internet communities. It is most commonly associated with online gaming, communities, and as it was originally meant to be, hacking. 
Despite its name, Leetspeak is used almost exclusively in written rather than spoken communication.
Leetspeak originates from the BBS system on the Internet, The purpose being to mock newcomers (or n00bs [Variant of newbie]), and to evade obscenity filters. Creative misspellings, unflattering ASCII art, and rude words obscured with ASCII are generally considered L33t5p34k with The most common variant is misspellings, and substituting characters for numbers.
Leet generally follows the protocols of common English, with the exception of neologisms. Certain grammatical errors may be placed on purpose.
- -Xor suffix. Replaces the "ER" and "R" phonetic devices. IE: Hacker to Haxor
- -Age suffix. Adds to the end of a adjective, or a verb in the infinitive form. IE "to fail" to "failage"
- -Ness suffix. Add to the end of a adjective, to make a verb.
- -D. Replaces the "ED" of a past tense verb, with "D". Ie: Failed - Faild