"/fireball" is a relatively new E2 chatterbox command which is used to "fireball" another user by publicly torching them in the chatterbox in a figurative ball of flame reminiscent of the classic Dungeons & Dragons fireball spell.
Technically a special form of "egg command," the /fireball command requires that the fireballing user have at least one easter egg, which is expended upon use of the command. Now for those of you who may at this point be wondering, "What level do we learn fireball?", the answer is that the user must also be at least Level 15, or higher to activate the command. Otherwise, the fireball publicly and shamefully "fizzles" to the mirth and mockery of one's fellows in the chatterbox.
When activated successfully by a level 15 user with at least one egg, the fireball command randomly triggers one of several automated messages describing the outcome of the fireball attempt. In all cases, the fireball command also awards the fireballee 5 GP (as opposed to the 3 GP awarded using all other egg commands), and also sends them a gentle and kindhearted message of love and comradeship.
To activate the /fireball command simply type the following into the chatterbox text box and hit enter or the "talk" button...
/fireball <username of user you wish to fireball>
Use this command for fun, flirtation, and profit! It's the Everything2 Way.™