In closing out this section, here is a mention of a pertinent feature for the multiplayer environment. You can send text messages back and forth on matters of anything game or non-game related, and even signal on the game map where a shared opponents' weak spot exists in their defences. Further, you can draw arrows and the like to plan out master strategy… a military strategist's dream come true. Any and all such demonstrations are highlighted in your civilization's assigned colour. These measures allow players to communicate graphically with greater efficiency and productivity.
I SPY WITH MY LITTLE CURSOR
Espionage is such a dangerous and risky venture that you will no doubt want to try it within the safety confines of Rise of Nations before too long. To get started, you needn't trouble yourself with the establishment of foreign embassies as is the case in the renowned Civilization series. Instead, use the spy unit's 'informer' ability to place an informant inside a building belong to another civilization. Once they are in place, you can actively monitor activity in and around it as well as what effort is being pursued within the structure itself. Thus eliminated is the return of the 'fog of war' effect whereby units moving out of visual range of an object renders it invisible once again.
To illustrate, Reynolds puts, consider a foreign marketplace (think the building itself, not the economy at-large). Without an informant, the most you can learn from it is what civilization it belongs to and what your present relation with that country is. With an informer planted there, you can additionally acquire data on how many resources the opponent in question has access to and of what type. Via the barracks, what and how many military units are at their present disposal becomes available to you. In an ongoing operation inside an enemy library, you can observe what kinds and numbers of technologies they have acquired and can also track the progress on their current scientific research. The bottom line: one spy does not give you carte-blanche abilities in watching over foreign affairs. Reynolds adds:
"It's not just all or nothing... put your informers where you want them... different buildings are useful for finding out different pieces of information, so there is a lot of good reason to go plant informers".
Rise Up: Reynolds On RoN 