Riddle, or puzzle, is a small challenge or mini-game. Examples of riddles within the game are: Tic Tac Toe, 2048, Lights Out, Trivia questions, Math questions.
Starting on the First Puzzle located at the First Whois, every server will have a riddle that can be found at the riddle.exe software, where the player will be challenged.
The moment the user nails the question, or completes the mini-puzzle-game, a new IP is discovered. This is the location of the next riddle, gradually harder than the previous one and with gradually better software.
Riddles converge to the upper Whois they are located.
So, for example, the First Puzzle will lead to other puzzles that will, gradually, lead to the First Whois.
Every Whois also have a puzzle in it that points to the next Whois.
Once you go to the next Whois, you must find the first puzzle within this Whois. It will be listed there, hopefully.