A strategic aid in many RPGs. a monster or demon is summoned to deal a large amount of damage or debuffs to the opponent, or to bless companions with buffs.
Titan Quest - 2006 - PC:
Unlike many other action RPGs, Titan Quest's approach to summoning is focused more on quality over quantity. Most spell casting classes have access to one or two powerful summoned creatures who, after being summoned, remain by the player's side until they die. With very few exceptions, there are no time limits to how long a summoned creature my remain in play as long as they have health. These creatures range from wolves, who fight primarily via melee attacks, to undead liches, who cast life leeching spells and have powerful auras, to nearly untouchable will-o-wisps. The chief downsides to summoning though are that the player can typically only summon one copy of each creature at a time and they usually require a very hefty investment of skill points to maximize their effectiveness.