This spell opens a portal to an Elemental Plane. A druid can
choose which plane (air, earth, fire, or water); a cleric opens a
portal to the plane matching his domain. The character can then
summon elementals from that plane.
When the spell is complete, 2d4 Large elementals appear. Ten
minutes later, 1d4 Huge elementals appear. Ten minutes after
that, one greater elemental appears. Each elemental has at least
5 hit points per HD (that is, at least 60, 80, or 100 hit points,
respectively). Once the elementals appear, they serve the
character for the duration of the spell.
The elementals obey the character explicitly and never attack
the character, even if someone else manages to gain control over
them. The character does not need to concentrate to maintain
control over the elementals. The character can dismiss them
singly or in groups at any time.
When the character uses a summoning spell to summon an air,
earth, fire, or water creature, it is a spell of that type. For
example, elemental swarm is a fire spell when the character casts
it to summon fire elementals and a water spell when the character
uses it to summon water elementals.