These rules are a merge of the armour rules in Ars Magica’s Parma Fabula supplement and on the Insula Maledictus saga website; with additional adjustments and limitations added. The intent is to provide guidelines for enhancements that are achievable for younger magi, and somewhat scalable to power levels.
Weapons
A magus can improve arms and armour with Rego and Muto spells, using either Herbam or Terram forms – or both for some weapons, the other as a requisite.
If the effects use the same arts, they can be added together and instilled as just one effect, adding +5 for constant use.
Melee weapons
| Effect | Levels | Notes |
|---|---|---|
| Increase Damage | +1 per magnitude | if more than +50%, must toughen weapon |
| Increase Accuracy | +1 per magnitude | if more than +1, Intellego requisite needed |
| Increase Defence | +1 per magnitude | if more than +1, Intellego requisite needed |
| Reduce Str required | +1 per magnitude | |
| Reduce Load | +0.5 per magnitude | to minimum of 0 |
| Effect | Levels | Notes |
|---|---|---|
| Increase Damage | +1 per magnitude | Max: +6 for edged, +3 for pointed. Max double the base value. Blunt weapons do not benefit from this. |
| Increase Toughness | -1 botch die per 2 magnitudes | 10th level requires double botch to break, 20th level requires triple and so on. Used with ReTe-damage increasing-effect above. |
Missile weapons
| Effect | Levels | Notes |
|---|---|---|
| Increase Damage of projectile | +1 per magnitude | |
| Increase Damage of weapon | +1 per magnitude | |
| Increase Accuracy of projectile | +1 per magnitude | Maximum positive modifier is +1. |
| Increase Accuracy of weapon | +1 per magnitude | Maximum positive modifier is +1. |
| Reduce Str required | +1 per magnitude |
Armour
| Effect | Levels | Notes |
|---|---|---|
| Reduce load (ReTe) | +1 per magnitude | Minimum loads: Hauberk -1 Half armor -2 Full armor -3 |
| Increase Soak (MuTe) | +1 per magnitude | Max double base value. |
Shields
Most shields are wooden, but Terram should be used for metal shields and Animal for leather shields.
| Effect | Levels | Notes |
|---|---|---|
| Reduce load (Rego) | +1 per magnitude | |
| Increase Defence (Rego) | +1 per magnitude | Max double base value. |
| Strengthen shield (Muto) | -1 per 2 magnitudes | Fewer botch dice, as in toughening weapons above. |
The effects should be applied with a description (like normal) which indicates how the item has been enhanced. All typical enchanted item limitations apply.
The Iron-Bound Tome 
So, would such enchanted weapons need to penetrate?
According to RAW? Yes, any effect needs to penetrate Parma.
Many troupes (myself included when I can) use a house rule that effects need to be more than strengthening or effects upon the items themselves. Parma Magica is a can or worms either way it is applied, so I think allowing these to ignore Parma does not break the spirit of the game.