stacking spells [magic]

[Tinman]

So it's been a while since I've GM'ed a standard magic campaign. I've run into a question about stacking spells and stacking spells & enchantments.

Situation1:
Mage with sk:18 casts haste.1 & shield.1.
this gives: move & dodge+1 / dodge,parry,block+1
Q: does he get +2 to dodge or only +1?

Situation2:
Mage has cloth armor suit with deflect.1 & fortify.1.(DR:2*)
Mage with sk:18 casts haste.1, shield.1, Armor.1.
this gives: move & dodge+1 / dodge,parry,block+1 / DR+1
Q1: does he get +2 DB or only +1?
Q2: does he get DR:3 or only DR:2?
.

[mlangsdorf]

Situation 1:
The mage gets +1 Dodge and +1 Defense Bonus (DB). Effectively, that's +2 to Dodge, but they're not the same thing and there are conditions where the DB may not apply. An attack that ignores magic will negative the Shield DB but not the Dodge.

Situation 2:
Shield and Deflect both provide DB, so they don't stack. Fortify and Armor both provide a bonus to DR, so they don't stack. He ends up with Dodge +1, DB 1, and DR 2*.

[Stormcrow]

In general, multiple spells' effects do not stack. See GURPS Magic, page 9.

However, I don't think you have your effects quite right. Haste adds bonuses to the subject's Move and Dodge scores. Shield adds a Defense Bonus to the subject. These are different things, so no stacking is involved.