This allows for actors to have a happiness value.
What is Friendship?
From the Bulbapedia page on Friendship
“Friendship (Japanese: なつき度 degree of emotional attachment), also often referred to by fans as happiness, is a measurement of how much a Pokémon loves its Trainer and enjoys being in their care. Friendship affects the evolution of certain Pokémon, the power of Return and Frustration, and the availability of a few in-game items and Ribbons. Certain events increase a Pokémon’s friendship (gaining a level, walking 256 steps) or decrease it (fainting, using herbal medicine).”
<friendship rate: x%> Adjusts the friendship rate by x%
<change friendship: sym> Changes the Friendship by the amount for the symbol
<friendship: x> Specifies the friendship value of the enemy