D&D 3E/3.5 COnverting 2e Spell resistance to 3e or 3.5 e

[herald]

Any suggestions?

 

[Pyrex]

Most of the creatures in the MM have SR ~equal to their CR+8, but that's not likely to help much.

I would go with something like the following. SR 50% = HD+10. For every 10% difference, add/subtract 1 from the final value.

i.e. SR 10% -> HD+6; SR 95% -> SR HD+14.

 

[andargor]

Any suggestions?

The problem is that caster level is involved, whereas 2e Magic Resistance was blanket.

This table illustrates the effect. Y is SR, X is caster level. So SR 25 is equivalent to 75% MR for a 10th level caster. Perhaps a good method would be to use (CR+20)*MR to determine SR.

Andargor

See attachment below.

 

[Scion]

nice chart

In 2e magic resistance was based on level. Somewhere (hidden away in some strange passage I'm sure ) it states that for every level above 10 the caster is the magic resistance is 5% lower, and for every level below 10 it was 5% higher.

I know it did somewhere, I forget where though and I am at work so cant dig through those musty old piles of books. I just remember pointing it out to several people in the past

 

[herald]

Thanks for the info, I was working on converting some magic items that gave SR, but I'm being to see that it's more like an apples to oranges comaprison. (At least for magic items.)

 

[Scion]

Which items do you mean?

For the most part it shouldnt be too bad. Just figure out how strong they were (or how strong you want them) look up how SR is done in items in 3rd edition and convert from there.

 

[dcollins]

Indeed AD&D (1st & 2nd Ed.) Magic Resistance was scaled to level, modified by +/-5% per caster level difference from 11th. In 1st Ed. that's stated at the beginning of every Monster Manual where "Magic Resistance" is defined.

The 3.0 Conversion Booklet dictated a conversion of SR = 11 + MR/5.

Yes, if you crunch the numbers that gives a +5% (1-in-20) advantage to the attacking caster under 3rd Edition rules.


Edit: Maybe andargor would be kind enough to edit his table above -- unfortunately it's not correct and the width has thrown off this thread's browser display.

 

[Staffan]

Indeed AD&D (1st & 2nd Ed.) Magic Resistance was scaled to level, modified by +/-5% per caster level difference from 11th. In 1st Ed. that's stated at the beginning of every Monster Manual where "Magic Resistance" is defined.

That was just 1st ed. 2nd ed MR was "straight" - no level-based modifiers. 3e was a step "backwards" in this regard (though I think it's better).

 

[andargor]

Indeed AD&D (1st & 2nd Ed.) Magic Resistance was scaled to level, modified by +/-5% per caster level difference from 11th. In 1st Ed. that's stated at the beginning of every Monster Manual where "Magic Resistance" is defined.

The 3.0 Conversion Booklet dictated a conversion of SR = 11 + MR/5.

Yes, if you crunch the numbers that gives a +5% (1-in-20) advantage to the attacking caster under 3rd Edition rules.


Edit: Maybe andargor would be kind enough to edit his table above -- unfortunately it's not correct and the width has thrown off this thread's browser display.

I decided to attach the Excel here, with the three methods.

EDIT: Method 2 and 3 are basically the same. The last formula given by dcollins is Method 3.

Andargor