Conjurations
Powers that have the conjuration keyword create objects or creatures of magical energy.

Unless a power description says otherwise, a conjuration can’t be attacked or physically affected, and
allies of the conjuration’s creator can move through
the space a conjuration occupies, but enemies can’t.

A conjuration uses your ability scores and defenses
to determine the outcome of attacks it makes and
attacks against it (if such attacks are possible).

Environmental phenomena and other forces have
no effect on a conjuration unless a power description
says otherwise. For example, a conjuration that produces an icy hand functions in a fiery, volcanic cavern
without penalty.

If a power allows you to move a conjuration, at least
1 square that the conjuration occupies must remain
within the power’s range. If you move far enough away
from a conjuration that it is no longer in range, its
effect immediately ends.

If a conjuration’s creator is slain, the conjuration
immediately ends.

Summoning

Powers that have the summoning keyword bring creatures from other planes to server you in a variety of ways.

Summoned Creature:

A creature you summon uses these rules, unless a power description says otherwise.

Allied Creature: When you use a summoning power, you create a creature that is an ally to you and your allies. The power determines where the summoned creature appears.

Your Defenses: The summoned creature's defenses equal yours when you summon it, not including temporary bonuses or penalties to your statistics.

Hit Points: The summoned creature's maximum hit points equal your bloodied value. When the summoned creature drops to 0 hit points, it is destroyed, and you lose a healing surge. If you have no healing surges left, you instead take damage equal to half your bloodied value.

No Healing Surges: The summoned creature lacks healing surges, but if a power allows it to spend a healing surge, you can spend a healing surge for it. The summoned creature then gains the benefit of the healing surge instead of your gaining it.

Speed: The summoning power determines the summoned creature's speed.

Commanding the Creature: The summoned creature has no actions of its own; you spend actions to command it mentally. You can command the creature only if you have line of effect to it. When you command the creature, the two of you share knowledge but not senses.
 As a minor action, you can command the summoned creature to take one of the following actions, if it is physically capable of taking that action: crawl, escape, fly, open or close a door or a container, pick up or drop and item, run, stand up, shift, squeeze, or walk.
 The summoning power determines any special commands you can give the summoned creature and gives an action type for each command. If a special command is a minor action, you can give that command only once during each of your turns.

Attacks and Checks: If a summoning power allows the summoned creature to attack, you make an attack through the creature, as specified in the power description. If the summoned creature can make a skill check or an ability check, you make the check. Attacks and checks you make through the creature do not include temporary bonuses or penalties to your statistics.

Duration: Unless the summoning power states otherwise, the summoned creature lasts until the end of the encounter and then disappears. As a minor action, you can dismiss the summoned creature.