Sword-and-Board, Meet Book-and-Crook!

I assume we'll have simpler versions of the classes aside more complex manifestations in D&DN. The simplest Fighter we've had was the "sword-and-board": best equipment proficiencies, best hp, best martial attack bonus, no extra rules. Why do the simplest Wizard and Cleric have spell lists and slot charts (more complex than the maneuver Fighters)?

We all tend to agree what Fighters can and can't reasonably do, but not magic. Magic, being an anything-is-possible matter, needs more limitation lest it turn into a game-breaker. Still, how to simplify the way we limit it?

Why, Dream, would anyone want to do this? Well, press this button:
It's not a trap...
People like different amounts of rules. As hinted in this blog, rules can be "ropes" for hanging onto (to enable), but those "ropes" can also be a "net" or "red tape" that inhibits. Rules can be walls that reveal a path to travel; they can also be a maze to those who already know where they want to go.

So, we could:

Dispense with charts for slots, making it basically MP. No chart needed!
Have a way to spend different amounts of MP/slots to create your spells on the fly. No spell lists needed!

Slots could even be "magic dice" rollable for for numerical effects (damage, healing, duration, stat transmutation) or spendable to add multiple targets, stretch range, or add non-numerical effects. More mutable than metamagic feats that give you a single trick 1/day, right?

Do you want to take about pitfalls with this method? Other ways of making a simple caster?

(Remember: the existence of a book-and-crook caster does not threaten the existence of a list-and-chart caster.)
I love this viewpoint! I'm running Lamentations of the Flame Princess now and thinking about giving the caster 1 spell point per day per level, and having the results be a combination of what the caster wants to do and any strangeness that I as DM see fit to include. The spell will scale to the casters level, but it will be a show stopper.

Having just a few spells per session like that I am going to give the MU a good selection of skills to choose from, good healing abilities, a useful familiar, and a few other toys that are as yet undecided. Perhaps "mind reading" techniques and sleight of hand magic tricks. Also some skill with alchemy and chemistry.

Thanks for the blog link. And thanks for posting.
 
Here's what I have so far for the familiar:


Familiars:
The magic user gains a familiar; a small toad, snake, or cat is common.  The familiar can also take the form of a token such as a broach, ring, or pendant; it can make the transformation once per day per level. The familiar is the magic user 's spy, and with total concentration (no movement, fighting, casting, etc) the magic user can see through the eyes of her familiar. 
 
If the familiar is killed, the magic user loses all of the bonuses of the familiar until the next full moon, when a new familiar will be attached to her. The MU also loses half of her HP’s rounded up; these hit points cannot be regained except through long rest.
 



The familiar has HP equal to half of its owners. AC will equal 14 + casters level.


The familiar can attack once per day per level, it hits automatically for 1 point and stuns the opponent for 1 round unless a ST vs. paralyze is made. The familiar is stealthy, it gets 2 dice + 1 per level to remain unseen.  


 Spell like powers: As the magic-user gains power so to does her familiar. The familiar may choose to cast a spell on its own or at the request of its owner. The only caveat is that no one must ever see the familiar use magic of any sort, including transformation. If someone does witness the animal performing acts supernatural then the magic-user must kill that person within 24 hours, or the familiar will attack the magic-user. The familiar will attack as if it has HD equal to the MU and will do 1d4 damage per round until it or the MU are dead.


-At second level the familiar may cast unseen servant once per day.


-At fourth level the familiar may cast Audible Glamour once per day.


-At sixth level the familiar may cast Knock once per day.


-At eight level it can locate an object once per day.


-And at tenth level it can assume gaseous form, also once per day.


The familiar is not sentient while in totem form, it must therefore be in animal form to use spell like powers. As long as the totem is on the person of the magic user then the conjurer gets +1 hp per level.
 


 


 
You could come up with a real simple spell caster if you took a model like spells slots or mana points and a basic outline of effects that spells could have for a specific cost.

Here are some examples:  cost is the spell level (slot) or points used.
 
1) single target damage spell:   cost-d8 + ability mod.

2) area of effect damage spell:   cost-d4 + ability mod, burst: 10 * cost feet (or some better scaling math that allows you to increase the area of effect, possibly the cost is the sum of the points/levels used for damage and area of effect).

etc...

Of course  this could be open ended, the player could suggest an effect and the DM could tell them the cost.


   

 
There was a d20 sourcebook for an alternate magic system called Elements of Magic. It was developed as a freeform magic for D&D or PF and uses magic points (MP) instead of spell slots. Though it didn't translate all spells to the letter it was close to emulating their effects. The benefit of that system was a caster could come up a new spell on the fly or create an alternate of an existing one.