Levels of interaction

MPS - no negative interaction or indirect interaction that rarely represents an optimal solution. Examples: A Feast for Odin, Gaia Project, Terraforming Mars, Wingspan, Dominion
Bash the leader - while its not necessary to achieve victory, players are capable of negatively impacting each other. Examples: Pax, Root, Catan
Zero sum interaction - interaction baked into design where players compete for limited objectives or conflicting goals. Examples: Twilight Struggle, Chess, COIN, War of the Ring
Cutthroat/Elimination interaction - victory is achieved by removing all opposition. Examples: Diplomacy, Coup, Lifeboats, Werewolf, Secret Hitler