Maps in ROTC: Ethernet are divided into rectangular zones and two teams fight over control of these zones.

Players can switch at will between two different forms: The flying, indestructible "Etherform" and a humanoid, weapon-wielding physical manifestation called a "CAT".

Players start out in Etherform and need to find a zone owned by their team in order to manifest as a CAT. As CAT, players take zones for their team simply by being inside the zone while no enemy CAT is also present in the zone. The zone then turns red or blue, depending on which team captured it. If CATs of both teams are present, the zone remains white.

The game is won if the opposing team has lost all their zones and has no more players manifested as CAT.

Things that are fairly unique about the game:
• Players can't "die". If a player loses all his health, he is simply forced back into Etherform.
• Dealing damage to enemies increases/restores a player's health.
• Players can fire and deflect target-seeking discs that bear an eerie resemblance to the discs in the movie TRON ;)
• All weapons draw from the player's regenerating energy. The energy consumed when firing a shot is restored when the shot hits an enemy.
• The same energy also serves as the player's armour, which means that firing your weapons without hitting an enemy makes you more vulnerable to damage.
• Players can ride their "Etherboard" to trade agility for speed.