There are four characteristics that change from D&D 3.5 to the Ajax Configuration, AC, Hit Points, spells/spell-like abilities, and damage.
Defence and Damage Reduction
When converting AC to DB and DR, first look at the AC in the monster's stat block. The total AC will be broken down into Size, Natural, Armour, and Dex mod. To get the monster's Damage Reduction, compare the Natural AC modifier to the table below. The monster's Defence bonus is calculated by adding size, Dex, and any class bonuses, if applicable.
Table 2.2: AC to DR
|+1 - +2||1|
|+3 - +4||2|
|+5 - +6||3|
|+7 - +8||4|
|+9 - +10||5|
Example: An Ogre has an AC of 16 (10 - 1 size, -1 Dex, +5 natural, +3 hide armour). The converted Ogre will have a DB of 8 (10 - 1 size, -1 Dex), and a DR of 6 (3 natural + 3 hide armour).
Hit Points and Wounds/Vitality
To determine a monster's WP/VP, treat the Hit Points as Vitality Points, and the Constitution score + size modifier as Wound Points.
Example: The standard Ogre has 29 HP, a Constitution score of 15, and a size modifier of 1. This gives the brute 29 VP and 16 WP.
Spells and spell-like abilities
Certain monsters have access to spells or spell-like abilities. In 3.X Ajax, this works as follows: All spells are treated as per the 3.X Ajax magic-rules, but with the monster's caster level substituted for the Spellcraft skill. Spell-like abilities work just as in 3.5.
All damage Dice are doubled.
[Picture source: Dave Rapoza]