Partially Used: Complex Spell Casting

This is something I've been working into a module of my own.  Complex Spell Casting.  Using normal spells together to create a new 'spell' or sorts.  Say a wizard knew the spells magic circle vs alignment, missile storm, and gust of wind.  by themselves they're very useful.  But when cast in a manner to weave all into a single enchantment... it would be once nice protective ward, with the effect of, if an evil enemy tries to enter the circle, they'd be hit by a gust of wind and a barrage of magic missiles as per the spells... and the effect would last as long as the magic circle spell would normally last.

Another example would be an aenea one... a sorcerer with transference, barrier of force, and circle of invisibility.  Using the complex spell would transfer the wizard to the destination point, which would be protected by a circle of force that prevents enemies from getting to him, and also renders him invisible.... adding additional casts of transference to the spell would allow him to transfere party members along with him to the destination point.

The complex spells would not be easy to cast, and perhaps could be something to consider for the epic magic overhaul proposal.  In the singleplayer module I'm working on, the preparation of the spells requires far greater concentration than normal spell casting, requiring a concentration check even when not in combat, and combat preparation has heavy penalties, needing to either prepare the spell in advance, or be well protected by henchmen or such.  The spells are cast onto a focus item (in my module, the caster's spell staff for example), and then actually 'cast' by using a unique power self/targeted off that focus item.

The actual complex spells would be determined by what's in the script of the item... I've only started playing around with it, so I dont' have many worked out yet... but a predetermined number of 'complex spells' puts forth a use for "spell books" that give the recipies for these complex enchantments.  No throwing any random spell into the enchantment and getting an effect.  Required material components is something that can be worked in as well.  If a caster throws in a few spells without researching the greater spell effect first, there a chance a nasty backlash could harm him.  If the spells thrown together dont' corrospond to an actual greater spell effect... boom.  If they do, but the caster is throwing together the enchantment 'on the fly', it could work, but has a chance also of going boom, depending on his or her skills.