If the mind believes something is real then it is real in every sense of the word - exept that it still may not have physical form.
Create Illusion is a second-level order magic spell that costs three spell points and forms a duplicate stack of creatures with a number of hit points based on the level of the caster. The illusion vanishes after combat ends, though combat will not end if one side still has illusionary creatures (even if they don't have any "real" creatures).
This is a very powerful spell in the hands of the hero. Unlike the Druid or Demonologist, who summon specific types of creatures, this spell can be cast on any creature present not immune to magic, giving the Order caster the ability to match almost any stack with its own nemesis.
This spell is a less powerful version of Phantom Image, however you might want to use it over that spell in some situations. Two casts of Create Illusion creates the same number of creatures as one cast of Phantom Image, but costs two spell points less. If you are in a situation where you're trying to get as many illusions for your spell points as possible and aren't in any danger of being swamped by enemy creatures (eg. in siege combat where the enemy is not moving out, or where you have all opposing stacks under control with Slow and Teleport) then you might want to cast the less powerful illusion spell.
The first cast on a specific creature type present during combat will create a new stack of that type, which is then generally placed as close as the tactical map will allow to the back row of the casting army. Subsequent castings (by any friendly caster) of this spell or of the more powerful Phantom Image on that same creature type will add to the same stack.
The top creature in the created stack may have less than the maximum allowed hit points, as the hit points are not rounded off "to the nearest creature." The caster must have the ability to create at least one-half the target creature's hit points in order to cast the spell on that creature type.
Genies also have access to this spell, summoning 15.2 hit points of creatures each, and in large stacks can create frightening numbers of illusions. A mere seven genies can summon one titan with 106 of its normal maximum 210 hit points.
Illusions will continue to fight even if their caster flees using Town Gate. If they win, the hero who escaped will get no experience for the victory.