The number of magic items that you can carry is theoretically infinite. However, a character's body can only stand to hold so much active on their person. Too many powerful magic items has a decidedly negative effect on the person holding them. Every character has a magic item bonus equal to half their level. This number is not rounded, because you can have items whose bonuses are half-points. A short table is given below for levels 1-20
Level
|
Item Bonus
|
Level
|
Item Bonus
|
1
|
½
|
11
|
5½
|
2
|
1
|
12
|
6
|
3
|
1½
|
13
|
6½
|
4
|
2
|
14
|
7
|
5
|
2½
|
15
|
7½
|
6
|
3
|
16
|
8
|
7
|
3½
|
17
|
8½
|
8
|
4
|
18
|
9
|
9
|
4½
|
19
|
9½
|
10
|
5
|
20
|
10
|
If you have a total magic item bonus equal to or less than this number, you are alright. However, if you go over this number, bad things happen. For every half point above your Item Bonus, you lose 1 Con until you remove that item. The loss is temporary as long as the item(s) are equipped. Note that only equipping items on yourself has this effect; storing them in a pouch or bad or weapons in their sheathes do not count towards this bonus.
Every magical item has a bonus of some sort, either +To Hit or +Damage or +Ability Score among others. Below, there is a table showing how much magic item bonus is given to an item for a particular magical ability. The list is comprehensive, but not complete. Certain special items will have to be given bonuses by the DM.
Note: There are -no- items that reduce To Hit/Damage and give bonuses to CR, or lower CR to give bonuses to To Hit/Damage. The reason is to prevent Mages and Melee classes from gaining disproportionately powerful items.
Enchantment
|
Magic Item Bonus
|
+X to AC/MR*
|
+X
|
+X To Hit (only)
|
+½X
|
+X To Damage (only)
|
+½X
|
+X To Hit/Damage
|
+X
|
+X To CR
|
+X
|
+10 HP
|
+1
|
+1 Attack or Prep/Round
|
+3
|
+1 Attack or Prep/Day
|
+1
|
+X To an Ability Score
|
+½X
|
+X Dice (e.g. d8 -> d(8+X))
|
+½X
|
+X Specialty Power **
|
+½X
|
+X Combo Power ***
|
+X
|
-X Ability Score+
|
-½X
|
-X Anything Else+
|
-X
|
* Mage's robes have an item bonus equal to -half- the MR bonus
of the robe.
** Specialty powers include: Sneak(only), Backstab Damage(only),
Damage vs. Special Type, Single Spell bonuses
*** Combo Powers include: Sneak and Backstab, Spell School bonuses.
+Minuses cannot be used to drop an item bonus to below the worth of the item. i.e. No +12 Dex, -3 AC, -3 MR items. That have an item bonus of 0. Since this item gives +3 AC and +3 MR, it is still considered to have an item bonus of +6.