Here's the general idea...
You encounter a LOGIN WINDOW. Chance to strike first!
You have to EQUIP a weapon first.
LOGIN WINDOW attacks and does 6 damage! You have 94 HP left.
You have the following in your INVENTORY:
> EQUIP pasSWORD
You EQUIP the pasSWORD.
LOGIN WINDOW attacks and does 4 damage! You have 90 HP left.
LOGIN WINDOW attacks and does 17 damage! Critical Hit! You have 73 HP left.
> CAST SPELL username
You CAST SPELL username. The LOGIN WINDOW appears to be off guard.
LOGIN WINDOW attacks and misses. You have 74 HP left.
You ATTACK with your pasSWORD doing 2,175 damage! Critical Hit!
You have slain the LOGIN WINDOW.
hmmm... or maybe you would create and name a character first... and that's where your username would come from. Then, you would make a custom pasSWORD, which would actually act as such. The problem of course, as Jesse pointed out, is that everybody would want to share their cool custom pasSWORD's.
Is watermelon sauce like Melonade?