Rock, Paper, Scissors design
In Five Nations vessels / biological creatures constitute your army. Each unit have different attributes, set of weapons and abilities which determine how they ought to be used in battle.
In most RTS games you would prefer if the players built several different kinds of units. A game could be interesting even with only one major unit type, but people may complain that it’s all about “massing units,” which will hurt your reviews. The standard way of enforcing this is to make sure that all units have at least one weakness. This weakness can be exploited by your opponent, and thus forcing you to mix up your units a little.
Let's look how the Rock Paper Scissors balance works in #fivenations: