Cast versus Armor
Cast versus Armor (CvA) is a factor in warding attack spells that reflects how well armor protects against magic. Lower CvA means the armor is more protective. Heavier armor types are harder to penetrate. Magical or enchanted armors protect the wearer better than non-magical or non-enchanted armors, and this differential also increases with the heavier types of armor.
These numbers apply directly to the warding roll. In practice, wearing heavier and magical armor is equivalent to having a higher target defense for any target.
Cast versus Armor by Armor Subgroup
| Armor Subgroup | Normal | Magical |
|---|---|---|
| Normal clothing | 25 | 20 |
| Robes | 20 | 15 |
| Light leather | 20 | 15 |
| Full leather | 19 | 14 |
| Reinforced leather | 18 | 13 |
| Double leather | 17 | 12 |
| Leather breastplate | 11 | 5 |
| Cuirbouilli leather | 10 | 4 |
| Studded leather | 9 | 3 |
| Brigandine armor | 8 | 2 |
| Chain mail | 1 | -6 |
| Double chain | 0 | -7 |
| Augmented chain | -1 | -8 |
| Chain hauberk | -2 | -9 |
| Metal breastplate | -10 | -18 |
| Augmented breastplate | -11 | -19 |
| Half plate | -12 | -20 |
| Full plate | -13 | -21 |
Per GM Cyper's post introducing CvA, use of a non-magical shield will provide -5 CvA, and a magical shield -10 CvA, which is not cumulative with armor. Functionally, this means that shields only provide a CvA benefit when Armor Group 1/clothing is worn.