From Guild Wars 2 Wiki
A summoned ally is an NPC that is summoned by the player and plays an important role in combat. They can be summoned by some professions, but also by using certain racial skills of all playable races.
 Types of summoned allies
- Spirit weapons
- Spirit Weapons are ghost-like allies summoned by guardians using utility skills. After creating a spirit weapon, the summoning skill is replaced by a sequence skill that will cause the spirit weapon to perform a powerful attack, destroying the weapon in the process. Guardians can maintain up to three spirit weapons, each of which follow the caster and can be attacked by foes; these allies survive for 20 seconds or until the caster uses the relevant sequence skill.
- Nature spirits are immobile spirit allies summoned by rangers using utility or elite skills. Each spirit provides a passive buff to nearby allies and enables a sequence skill, used to harm foes or support allies.
- Fellow thieves
- Fellow thieves are summoned by thieves using various skills and once summoned they will fight alongside the player until slain or their duration expires.
- Elementals are summoned by elementalists using a Glyph of Elementals or Glyph of Lesser Elementals; the type of elemental is determined by the caster's current attunement: air, earth, fire, and water. Elementals last for 60 seconds or until slain.
- Illusions are mind tricks that mesmers manifest physically using a variety of skills, and are summoned with the same appearance as its caster. Although they are usually directed at a specific target, anyone can see and attack them. They can only exist so long as their target is alive and can only be dispelled by the caster or by foes attacking the illusion directly. Mesmers can maintain up to three illusions at any one time, with newer ones replacing the oldest ones (regardless of the health of the existing illusions).
- Minions are dead flesh and bones animated by necromancers using slot skills. Most minions follow the caster, although a few remain fixed in the location at which they were created. Once summoned, the minion will automatically attack hostile targets, can be influenced using a corresponding sequence skill, and can be resummoned if destroyed. Necromancers can create up to six different minions, depending on their build.
 Upgrade components that affect summoned allies
- Superior Rune of the Ranger (rank 6 – increases damage while you have a companion)
 Upgrade components that summon allies
- Superior Rune of the Ogre (rank 4 – Rock Dog)
- Superior Rune of the Golemancer (rank 6 – Golem)
- Superior Rune of the Lich (rank 6 – Minion)
- Superior Rune of the Pirate (rank 6 – Parrot)
- Sigil of Demon Summoning (Fleshreaver)
 See also
- In the Reddit Guild Wars 2 developers AMA of 14 December 2011, Jonathan Sharp misspoke about elementalists having access to familiars. This was subsequently corrected, but did not rule out summons via elementalist skills as a possibility.