Stacking Ability Modifiers (3.5e Variant Rule)

Stacking Ability Modifiers
The random number generator is a fragile thing in D&D, where going even 8 or more from the middle of it can result in rolls that virtually always hit or miss which takes the point out of rolling in the first place. As ability modifiers can reach up to +12 (or more with racial/class bonuses), stacking ability modifiers on top of each other in regards to d20 rolls can easily get out of hand. This variant takes a look at two such cases found in the core rulebook, and gives solutions to them. These solutions can then be used in other, similar cases.

Stacking Ability Modifiers to AC
The monk gains the ability to add their Wisdom modifier to AC on top of Dexterity. This can lead to them outstripping virtually every other character in terms of AC, though not necessarily in survivability if they get automatically hit. To remedy this, we use the following rule:


 * The monk's bonus to AC from Wisdom does not stack with armor or armor enhancement bonuses. Furthermore, whenever the monk would normally have the benefit of his Wisdom modifier to AC, he also gains DR/-- equal to his Wisdom modifier up to a maximum equal to his class level in the monk class. This does not stack with DR from any other source, including that of the barbarian class.

For example, a first-level monk with 16 Wisdom would have DR 1/-- while not Helpless, which would increase to DR 2/-- at second level, and would gain a bonus to AC equal to three. This models the Monk learning to moving the smallest amount without breaking their posture in order to take as little damage as possible. A crushing blow that would have caved in their head becomes just a clipping strike, while a sword swing that would have left them disembowled leaves only a scratch, or even misses entirely (should it deal no damage).

Stacking Ability Modifiers to Saves
The paladin gains the ability to add their Charisma modifier to their saing throws, which can be easily problematic. In order to remedy this, we have the following rule:


 * When a Paladin would make a saving throw, he may replace the normal ability score used with his Charisma modifier.

For example, let's say a Paladin had a Will save of 4 (Base) - 1 (Wisdom) + 2 (Cloak of Resistance) for a total of +5, and had a Charisma modifier of +5. When forced to make a Will save, he would replace his Wisdom modifier with his Charisma modifier, rolling +11 on his Will save (4 Base + 5 Charisma + 2 Cloak of Resistance).

Conclusion
Use these rules to keep characters on the RNG, while still giving meaning to their character abilities. Remember to use this for similar equivalents; for example, the Swordsage would gain their Wisdom modifier as DR while in light armor, and the Crusader would be able to roll twice for their Will saves, using their Charisma bonus instead of Wisdom on their second roll.