From ThresholdRPG Wiki

There are three kinds of dominance in Threshold.

Religious Dominance

The religions of Threshold compete for favor primarily via sacrifice, but also through the actions of their clergy.

Clan Dominance

Clans compete for dominance as well, seeking the Hand of Vindicator. Dominance in this way is sought primarily through the tribute of resources.

City Dominance

There are many benefits to prosperity that are enjoyed if your city, usually Sable or Thrace are dominant. Dominance here is sought via resources or by the use of city vouchers obtained as rewards for completing city tasks.