Skip to main content

Linneman's Alternate Magic

Jonathan Linneman, over on the Monstrous Matters blog, posted a really intriguing idea for a simplified magic system.

He proposes a sister mechanic to Hit Dice: Magic Dice. If you want to level up in spell casting instead of fighting, you get a Magic Die instead of a Hit Die. When casting a spell, roll a pool of 6-sided dice equal to your MD.

MD pool ≥ Spell Level x 5.

Success: Spell is cast. Remove one die from MD pool (minimum of 1).

Failure: Spell is not cast. Add one die to MD pool.

This looks great. I love the idea of taking the bookkeeping out of spell casting. I love mechanics that make failure functional. And this looks elegant. But will it actually work?

I went over to anydice and looked at the numbers. I ran the Spell Levels up to 6 and the MD Pools up to 12, because my brain defaults to B/X magic.

Spell Level
Target

MD Pool
Minimum Roll
Maximum Roll
1
5

1
1
6
2
10

2
2
12
3
15

3
3
18
4
20

4
4
24
5
25

5
5
30
6
30

6
6
36



7
7
42



8
8
48



9
9
54



10
10
60



11
11
66



12
12
72


MD Pool
Percent chance of succeeding per Spell Level
1
2
3
4
5
6
1
33





2
83
17




3
98
62
9



4
99
90
44
5


5
100
98
78
30
3

6
100
99
93
63
21
2
7
100
99+
99
86
50
14
8
100
99+
99+
96
76
38
9
100
99+
99+
99
91
65
10
100
100
99+
99+
97
84
11
100
100
99+
99+
99+
94
12
100
100
99+
99+
99+
98

Alright, so problems begin to creep up pretty early on. If you're replacing Vancian memorization with a chance of failure, you need a pretty good chance of failure. But Spell Level x 5 simply isn't steep enough a curve. Magicians quickly become unstoppable firehoses of magic.

But if you change the Target numbers like so:

Spell Level
Target




1
5




2
15



3
25




4
35




5
45




6
55










You get a success rate that is much more in keeping with the Old School progression:

MD Pool
Percent chance of succeeding per Spell Level
1
2
3
4
5
6
1
33





2
83





3
98
9




4
99+
44




5
100
78
3



6
100
94
21
<1


7
100
99
50
1


8
100
99+
76
9
<1

9
100
99+
91
28
<1

10
100
99+
97
53
4
<1
11
100
99+
99+
76
15
<1
12
100
99+
99+
90
34
2

You can fine tune the Target numbers to more closely follow the Oe/BX progression (something along the lines of 5, 12, 16, 20...), but I was drawn to the idea of a numerical sequence that could be easily memorized.

This mostly looks good to me. A 1MD wizard is going to miss a lot, but will be pretty decent with 1st Level spells once they advance to 2MD. 

A 3MD wizard is going to be a dab hand at 1st Level, but will need to fail at least once to have a decent shot at a 2nd Level spell.

It's not perfect, by any means. You'd have to be level 15 before you could reliably cast a sixth Level spell. Maybe drop the Target for 6th Level spells to 50? Breaks the pattern, but gives a 12th-Level caster a 1-in-10 chance of succeeding.

Also, the dynamics of adding and dropping dice based on failure and success probably has all sorts of implications that need to be play-tested. F'rinstance, what do you do when a player purposely fires off higher level spells in order to bank enough failures and build up their MD pool?

Possible solutions include limiting the number of dice you can carry forward, limit the duration, or instill a calamity/corruption risk to casting above your level.

Howsabout this? Succeed or fail, if your roll results in any 1s, you must roll below:

1d8 + # of 1s
Calamity
1-4
No effect.
5
Inconvenient side-effect. GM picks something about the spell effect to go wrong.
6
Addled. Lose 1d4 INT or WIS. for 1d6 Turns.
7
Exhausted. Lose 1d4 STR, DEX, or CON for 1d6 Hours.
8
Spell Forgotten. Will need to be relearned.
9
Temporary mutation. Lose 1d8 CHA for 1d6 Days. GM makes up your crazy new appearance.
10
Permanent mutation. Roll on some chart or another.
11+
Extra-planar intrusion. You summoned something troublesome.

There's a lot to work out, here, and I present this information in the hopes of continuing the conversation. This could be quite a pretty little system.

Comments

Popular posts from this blog

Knaves, fancypants

I've prepared a new layout document of Ben Milton's Knaves . Knaves is a great, light rules set that has an extremely elegant core mechanic while retaining total compatibility with OSR material. It's pretty much the rpg of my dreams. This document contains the complete rules, plus a bunch of useful hacks from the community, plus a few of my invention, plus some useful resources from Ben Milton's previous effort, Maze Rats . EDIT: I've updated the layout to fix errata and make a few tweaks. Further, I've made 3 variations: KNAVES TABLET LAYOUT The Tablet Layout is meant for scrolling on screens, and contains hyperlinks. KNAVES SPREAD LAYOUT The Spread Layout is set up to print on Letter-sized paper. KNAVES A4 LAYOUT The A4 Layout is set up to print on A4 paper, and is probably the most elegant of the three versions. This is presented with generous permission from Ben Milton, and should in no way be an excuse for not purchasing a copy of Knav

Maze Rats by Post

In my previous post , I reviewed a bunch of my favorite rulesets for optimization for Play-by-Post. It occurred to me almost immediately that I hadn't really thought about Maze Rats enough. In fact, I'd mis-remembered and mischaracterized it. Upon reflection, one of the mechanics I took issue with is actually a big strength. Re-reading the rules, it seems like just a few very simple hacks could make it a highly-optimized PbP game. As follows: Danger Rolls are rolled by the GM. Danger rolls usually fail, so it is in the player’s interest to describe their actions plausibly and mitigate as many risks as they can, in the hopes that they don’t trigger a danger roll. 2d6 + ability bonus ≥ 10 If you have taken enough precautions to have a distinct advantage in an action, but not enough to have eliminated the distinct possibility of danger, the GM will give you a roll with advantage. 3d6 keep 2 + ability bonus ≥ 10 Because each character only has 3 ability scores (S

Reviewing Rules for Play-by-Post Optimization

I’ve played a lot of PbP games: all your favorite flavors of OD&D, AD&D, and their retroclones, Call of Cthulhu, Marvel Superheroes, Traveller, Dungeon World, etc. ad nauseam. In almost every instance, I forgot what ruleset we were using at some point. Which is a good thing. Once chargen is over, you spend a lot more time describing your characters actions and poring over the GM’s descriptions than you spend interacting with rules. When you do roll, it’s usually a combat to-hit roll, which you’ve probably programmed into the online dice-roller as a macro. Pretty much any game will work for PbP. But that doesn’t mean there aren’t points of possible optimization. Point 1: Resolution. Anything that can keep the action moving is a boon to PbP. A game that requires a back-and-forth exchange of information to resolve an action is going to progress very slowly. A good rule of thumb is that it’ll take 2 or 3 days to get a response from any given player. At that pace, an exch