OSRenstein: how I'm rewriting the spells of D&D

I'm not sure what day I started writing on, but I've got about 15 pages of rules written with 9 more pages drafted out with little details and bullet points of what I want to write. I've been sending my gaming friends copies of the pdf as I update it and I promised them that I would have the 1st-level wizard spells done with the next version.

This is how I'm writing the spells, I'll use the Shield spell as an example.

The first thing I do is write down the important details of each version of the spell as it has appeared throughout the various versions of the official D&D rules (except 4th edition because fuck that edition):

basic - affects caster, lasts 20 minutes
magical barrier between the caster and his or her enemies.
It moves with the spell caster.
gives AC 2 vs missiles and AC 4 vs other attacks

1e - lasts 5 rds/level
invisible barrier before the front of the caster
negates magic missile attacks
gives AC 2 vs hand hurled missiles (axes, darts, javelins, spears, etc.)
gives AC 3 vs small device-propelled missiles (arrows, bolts, bullets, manticore spikes, slingstones, etc.)
gives AC 4 against all other forms of attack
also adds +1 to the magic-user’s saving throw vs. attacks which are frontal
all benefits of the spell accrue only to attacks originating from the front

2e - lasts 5 rds/level
invisible barrier in front of the wizard
negates magic missile attacks
gives AC 2 against hand-hurled missiles (darts, javelins, spears, etc.),
gives AC 3 against smalldevice-propelled missiles (arrows, bolts,bullets, manticore spikes, slingstones, etc.)
gives AC 4 against all other form of attack
also adds a +1bonus to wizards saving throws against attacks that are frontal
benefits apply only if the attacks originate from in front of the wizard

3e - lasts 1 minute/level
creates an invisible, tower shield mobile disk of force that hovers in front of caster
negates magic missile attacks
gives +4 shield bonus to AC. applies against incorporeal touch attacks, since it is a force effect.
shield has no armor check penalty or arcane spell failure chance
unlike a normal tower shield, you can’t use the shield spell for cover

5e - lasts 1 round
invisible barrier of magical force appears and protects you
Until the start of your next turn, you have a +5 to AC, including against the triggering attack
you take no damage from magic missiles

This tells us a lot about the Shield spell, and it also shows us how D&D has changed over the years. Imagine that!

I want to strip the spell of its complexity, much like 5th edition has, but I want to retain a long duration, similar to the Basic version. Notice also how the Basic version of the spell gives a much bigger AC bonus than all the other versions of the spell. I like that most versions of the spell completely negate Magic Missile attacks.

Shield (abjuration)
Creates a magical barrier in front of the wizard that negates all missile attacks and provides +4 Armor against anything attacking the wizard from in front.
Casting: 1st level, 1 MP.

Looking at every version, that's the Shield spell as I want it to be played in my rules. This is what I've written before I've considered any of the specific modifications my custom rules might apply to it yet. I'm already using Magic Points instead of a Vancian system, and that's baked into the Casting descriptor.

I've included the ability to cast a spell as a reaction in my rules, and I think Shield fits perfectly as a spell that a wizard may want to cast in the heat of the moment. The only real decision I have to make is whether I want this to be a spell that the wizard casts and then it just exists for the duration of the spell, or if I want to change it into a spell that must be concentrated on to maintain.

I'm going to choose the latter, but I also want wizards to have the option to cast it as a spell they don't need to concentrate on, something with a long duration. My Magic Point system already gives me the perfect way to make this a potentially powerful spell at higher levels simply by adding a scalable duration.

Adding all of this means the final version of the spell looks like this:

Shield (abjuration)
Creates a magical barrier in front of the wizard that negates all missile attacks and provides +4 Armor against anything attacking the wizard from in front. Can be cast as a free action, but the wizard must concentrate to keep the spell active.
Casting: 1st level, 1 MP. Each level added to the MP cost allows Shield to last for 10 minutes without being concentrated upon.

I might need to fix the wording of "Each level added to the MP cost" but for now it works, and this is only the fourth spell I've worked on so far.

The list of 1st-level spells I'm working on is
Alarm (abjuration)
Cantrip (all)
Charm Person (enchantment)
Chill Touch (necromancy)
Find Familiar (ritual)
Floating Disc (invocation)
Grease (summoning)
Hold Portal (transmutation)
Light (transmutation)
Magic Missile (invocation)
Phantasm (illusion)
Read Languages (divination)
Read Magic (divination)
Shield (abjuration)
Sleep (enchantment)
Spook (necromancy)
Steed (summoning)
Ventriloquism (illusion)