This is a perversion of the original 3x3x3 that Cortex and Firefly first used. This is intended to generate NPCs for a campaign as part of character generation. Each player will have 6 NPC cards. I've dropped Contacts from the selection, preferring to focus on the two subjects player's will care more about: Rivals and Allies.
On all six of these cards a player needs to list their name. After a "-" they should note what kind of NPC this is, Rival or Ally. Each player can define two of the following for each NPC: A Name, their Character's Relationship with them (in one or two words), or one truth about them. If they want, they can also write down which Icon that NPC is associated with. Not everyone is associated with a particular Icon, but some PCs might want specific allies and rivals as their connections to particular Icons.
Remember, there needs to be room left for other players after you're done with your part with it.
After everyone has detailed their very first Ally, everyone hands one of that to the player to their left. When a player receives another player's Ally, they need to first list their name on the card some where. Next, they need to decide- is this an ally, rival or a contact of theirs as well? If so, list that next to their name on the card.
That player will also have the chance to play this NPC against the player who created it- if the NPC is around, most likely the GM will hand them their card and let them handle that NPC unless something important or story related is needed (even then, the GM may still just give that player the card and let it happen anyway).
That player also gets to define up to 3 truths about this NPC as well.
[An Aside: What is a Truth?
A Truth is one true thing about a NPC. It can be somewhat broad, but always should be precise in scope. You are defining a single thing about the NPC, which is always true, but not necessarily always "known."]
This process is repeated until each PC has at least 3 allies and rivals. This is a great step for players to continue building connections with one another. Each NPC should have a player assigned as RP'er, and each NPC should have some of it's background generated by another PC.
This should help to create a NPC web around the PCs, which always is handy. And most of it should be player generated, helping give them some buy in.