Saving Throws variant
by Giampaolo AgostaOne of the key assets of OD&D is, in my opinion, modularity. Subsystems tend to be independent of each other, much more than in newer editions, so it's easier to swap out some system and replace it with something else. Since some people dislike the Saving Throws system of OD&D, here is a different version, based on 4e defenses.
Saving Throws (or Defenses)
In this variant, Saves are handled as attacks vs defense opposed checks; one of the two is static (add 10 to the bonus), the other dynamic (add 1d20 to the bonus).
Attack Bonus (AB) = 1/2 level + ability score bonus + class bonus + effect bonus
Defense Bonus (DB) = level + ability score bonus + class bonus + race bonus + magic bonuses (ring of protection)
Note that is is irrelevant whether it is the attack or defense to be static -- if you want to reduce DM rolls, you might even let PC attacks and defenses be dynamic, and all NPC/Monster attacks and defenses be static. OTOH, if you want more variance, you can make both attack and defense dynamic for everyone.
However, the standard procedure should be to choose one version (either dynamic attacks and static defenses as in 4e, or static attacks and dynamic defenses as in other editions) and stick with it (for simplicity, at least).
Defense types
4e uses only three defenses, each ruled by two different ability scores. This leads to min-maxing by ability score dumping. To avoid this, and to more closely mirror OD&D Saving Throws, I propose to use 6 defenses, one per score. Here are the correspondences with Saving Throws (as per the optional rules of Black Box and RC):
Dex (Wands, Dragon breath, Death Ray)
Wis (Rod, Staff, Spells)
Int (Mind attacks)
Con (Poison)
Str (Paralysis, Turn to Stone)
Cha (Energy Drain)
As you will have noted, there is an addition: Charisma doesn't affect any Saving Throw in OD&D. However, one problem of OD&D is that there is no way to avoid Energy Drains, which are also permanent. I propose to use the missing Charisma ST to handle Energy Drain attacks, either to provide a way to avoid it, or to provide a way to get back the drained level (similar to shaking off a Charm spell, except in this case instead of using Int to find when you are entitled to the next save, I'd use Con or Wis).
If you prefer 3 saving throws only, it's easy enough to merge of defenses -- Str with Con, Int and Cha with Wis. You may still choose whether to have ability score bonuses as in 3e (one key ability per defense) or 4e (two abilities per defense).
Effect bonuses
Different effects may give bonuses to the AB. The following list should cover most issues.
Spells: 1/2 level of spell
Energy Drain: number of drained levels
Dragon Breath: small 2, large 4, huge 6, guardian 8, Immortal 10
Wands, Rods: 1/2 level of equivalent spell
Staves: to hit bonus of Staff
Poison: ST penalty
Paralysis, Petrification, Death Rays: usually none
All: if there is a ST penalty, consider it as an effect bonus
Class Bonuses
The following bonuses are inferred from the ST tables of OD&D -- you'll easily note that, e.g., when a class has good Dragon Breath save it has a bad Spells save, and the same goes for Poison and Paralysis. I just took this differences and translated them to small (+1 or +2) bonuses that balance out.
| Con | Str | Wis | Dex | Int | Cha | |
| Cleric | +2 | 0 | +2 | 0 | +1 | 0 |
| Fighter | +2 | 0 | 0 | +2 | 0 | +1 |
| MU/T | 0 | +2 | +2 | 0 | +1 | 0 |
Foresters (Elves)save as multiclass F/MU, getting the best of the two bonuses. This is not a problem here for balance (it is balanced through the standard multiclass rules applied to obtain the Elf race-class).
Attack bonuses are needed to represent the nonlinear ST progression of OD&D. Allow a +1 bonus to Companion level spellcasters, and a +2 bonus to Master level spellcasters (and traps, dragons, etc).
Race Bonuses
Dwarves have more or less the same ST as Fighters of higher levels, with the exception of worse Dragon Breath saves.
I suggest converting these to just Poison and Spells bonuses.
Dwarf/Halfling: +2 Str & Wis Defenses
However, if Dwarves top at 12th level, then they should add 3 times their level (rather than just their level).
The same goes for Halflings.
Elves have no special bonus. As mentioned above, they just have typical multiclass saves (best of the two classes).
OK, let's do some maths on the above discussion
Let us consider three pairs of attack spell and saving throws, at different levels, on the following formulae:
Formula A
Att = 1d20 + 1/2 lvl + ab. + 1/2 spell lvl
Def = 10 + 1/2 lvl + ab. + ring of protection
Formula B
Att = 1d20 + 1/3 lvl + 2 + ab. + 1/2 spell lvl
Def = 10 + 1/2 lvl + ab. + ring of protection
Formula C
Att = 1d20 + 1/4 lvl + 2 + ab. + 1/2 spell lvl
Def = 10 + 1/2 lvl + ab. + ring of protection
Formula D
Att = 1d20 + 1/3 lvl + ab. + 1/2 spell lvl
Def = 10 +2/3 lvl + ab. + ring of protection
Formula E
Att = 1d20 + 1/2 lvl + ab. + 1/2 spell lvl
Def = 10 + lvl + ab. + ring of protection
Assuming round up in level division, and +1 ability score for attacker, +0 for defender.
1) MU1 casts Charm Person on Fighter 1
OD&D: 25% save chance
A: 1d20 + 3 vs 11 -> 35% save chance
B: 1d20 + 5 vs 11 -> 25% save chance
C: 1d20 + 5 vs 11 -> 25% save chance
D: 1d20 + 3 vs 11 -> 35% save chance
E: 1d20 + 3 vs 11 -> 35% save chance
2) MU8 casts Polymorph Other (4) on Fighter 8
OD&D: 60% save chance (base), 65% with ring of protection +1
A: 1d20 + 7 vs 15 -> 35% save chance
B: 1d20 + 8 vs 15 -> 30% save chance
C: 1d20 + 6 vs 15 -> 40% save chance
D: 1d20 + 6 vs 17 -> 50% save chance
E: 1d20 + 7 vs 19 -> 55% save chance
3) MU25 casts Polymorph Any Object (8) on Fighter 25
OD&D: 80% save chance (base), 95% with ring of protection +3 or better
but Polymorph Any Object, like most high level spells with saving throws, imposes a -4 penalty to the roll, thus reducing the save chances by 20% to 60% without ring and 75% with ring of protection +3
A: 1d20 + 18 vs 26 -> 35% save chance
B: 1d20 + 16 vs 26 -> 45% save chance
C: 1d20 + 14 vs 26 -> 55% save chance
D: 1d20 + 14 vs 30 -> 75% save chance
E: 1d20 + 18 vs 38 -> 95% save chance
Option D seems the more fitting. It doesn't make major changes at high levels, but spells become slightly more effective at Basic levels and slightly less so at Expert levels. Option E is also acceptable -- it fits better at Expert levels, but less so at high levels.
An equivalent option to D can be:
Att = 1d20 + 2/3 lvl + ab. + 1/2 spell lvl
Def = 10 + lvl + ab. + ring of protection
A perfect match cannot be obtained with linear progressions, because STs have a non-linear progression -- unless of course one chooses to use a non-linear progression for either attack or defense -- which is entirely possible.
STs improve by 2/3 up to level 12 in OD&D, and by 1/3 beyond level 12.
Thus, it is possible to fix defense improvements at +1 per level, and attack improvements at +1/3 per level up to level 12, and +2/3 per level beyond level 12. This exactly reproduces the OD&D save chances when two opponents of equal level face each other.