Set in the 40th century, Starsiege: Tribes set two teams against each other in huge online battlefields. Including five distinct game modes, Tribes includes vehicles and jetpacks to help players get around. It incorporated lots of customization options, allowing players to build their own loadouts from a wide range of weapons. Players quickly discovered that if you timed your jumps properly while going downhill, you could accumulate momentum - a trick called "skiing." This became so popular it was built in as a feature in the ensuing sequels. Tribes was noteworthy because of its great balance and heavily teamwork-focused gameplay.