Ok, so I've attempted to do a layout/flowchart of the project I'm working on. I've printed it in PDF format hoping to make it more visible.

 

I don't know if this clears up my though process or not, but...

 

I'm thinking, use the Arduino to scan the RFID, pass the data to the RPi which will then transmit the data to the SQL DB on a centralized server. The server sends back which team the player is on to  the RPi. The RPi then tells the Arduino which color to illuminate the LED's at the room's door. The player's can join different teams in each game, therefore the centralized DB will keep track of all that.

 

Make sense? And am I overthinking/working this? Do I need to use both the Arduino AND RPi or can this be accomplished with just one of these devices.... and if so, which one?