This year, the Global Game Jam will be hosted in a very special location in Rome: the Tempio di Adriano! It is a temple to the deified Roman emperor Hadrian, now incorporated into a later building in the Piazza di Pietra ("Piazza of Stone").
The temple is centric, deep in the centre of Rome (in case you're in for some touristic brainstorming!) and with restaurants, bars, and supermarkets in close proximity. It has already been used for events, so wi-fi and other technological necessities are not a problem. In fact, the building has been hosting the Stock Exchange of Rome for years.
The address is Adriano Temple - Piazza di Pietra, 00186 Roma. Scroll down for travel information.
For more information on the building, check the entry on Wikipedia.
Being in the centre, the temple is surrounded by many bus lines. To find the one that works best for you, use the local transport website to trace a route. The closest Metro stops are "Barberini" on line A (7 minutes by foot), or Cavour on line B (10 minutes away).
Regular bus tickets (BIT) are 1,50€ each and last for 100 minutes, and allow you to travel once on the metro and take as many buses as you wish within the time limit. We advice not to go for cumulative tickets (like the daily or 3-days one), you will do better with single tickets (and spend less).
Rome has two main airports, Ciampino and Fiumicino, both connected to all of the main locations in the world by direct flights. Ciampino is usually the cheapest one, as it is served by Ryanair.
Both airports can be reached by bus or train from the main station (Roma Termini). Buses are usually cheaper (between 4€ and 7€), while trains are more expensive, and not necessarily faster. Go for the bus!
Additionally, there are several bus companies that leave from/to the station and back. You don't need to buy the tickets in advance, just go there and get the one that leaves first!