Armor & Defenses

Here's an interesting thought:

Should more durable characters (A) get hit less or (B) be able to get hit more or (C) both?

For example, in AD&D, a fighter has good AC (plate mail + shield) compared to a wizard. The fighter also has many more HP. In comparison, in 4E, many characters can attain similar defenses, but the tankish types have more HP and healing surges, which allows them to take more of a beating.

If the more durable characters get hit less, then it makes their HP "more valuable." A HP on a plate-clad fighter is less likely to be lost than a HP on a squishy mage or thief. This makes fighter types a top priority for receiving healing magic in many games with strategic players. One downside of this scheme is that it might be boring for the tank if he never takes damage. Also, it can lead to swingier combat, where the tank goes from hale to hurting in a few lucky rolls.

If the more durable characters can get hit more often, then their HP are about as valuable as anyone else's. It also allows others to "off-tank" for a few rounds if needed, because their defenses are adequete.

If you use both, then the durable characters are potentially really, really much tougher than their counterparts.

Right now I've decided to opt largely for option B, with a touch of C. That is, everyone can attain similar ACs for the most part (although dedicated plate-mail users will still have an edge). That AC will be around 4 on a D6 (AC ~14 on D20), so they'll get hit about 50% of the time. More durable characters will just have to have more HP to make up for their similar ACs.

So with that in mind, here's my current revised rules for OD&D.

Armor: Characters may select between no armor, cloth, leather armor, chain mail, or plate mail.

As a note, these figures use ENC in stones, AC on a D6 (also rough hacks for D20), and cost on a notional scale from 1-7 that is still just a figment of my mind.

PLATE MAIL
ENC 3 STONE
AC 5 (on D6) or AC 17 (on D20)
COST 5 coin (upkeep 1 if fail ARMAMENTS check)
PROPERTIES: Individuals in plate mail always lose initiative rolls and take a -1 penalty to speed. Grants CA to bludgeoning.
N.B.: "Upkeep 1" indicates that after each quest (approx 3 milestones), the wearer must either expend 1 coin or have their armor degrade to AC 4. The wearer may make an ARMAMENTS skill check to avoid having to pay this cost, representing doing the MX themselves.

CHAIN MAIL
ENC 2 STONE
AC 4 (on D6) or AC 14 (on D20)
COST 3 coin
PROPERTIES: Individuals in chain take a -1 penalty to speed.

LEATHER ARMOR
ENC 1 STONE
AC 3 (on D6) or AC 12 (on D20)
COST 1 coin
PROPERTIES: +1/6 chance to surprise others. AC 5 vs. Opportunity Attacks from movement.
AGILITY BONUS: Characters may apply their Agility modifier to their AC (D20); if using D6 based to-hit rolls, a +2 agility modifier allows you to add +1 to your AC, and a +5 agility mod allows you to add +2 to your AC.

CLOTH ARMOR
ENC 1 STONE
AC 3 (on D6) or AC 10 (on D20)
COST 1 coin
PROPERTIES: May be worn under heavier armor; if this is done, such armors no longer suffer vulnerability to bludgeoning weapons. If worn alone, it removes vulnerability to slashing weapons suffered when not wearing any armor. There is no other effect.
AGILITY BONUS: Characters may apply their Agility modifier to their AC (D20); if using D6 based to-hit rolls, a +2 agility modifier allows you to add +1 to your AC, and a +5 agility mod allows you to add +2 to your AC.

NO ARMOR
ENC 0 STONE
AC 3 (on D6) or AC 10 (on D20)
COST 0 coin
PROPERTIES: +1/6 chance to surprise others. AC 4 vs. Opportunity Attacks from movement. Grants CA to slashing weapons.
AGILITY BONUS: Characters may apply their Agility modifier to their AC (D20); if using D6 based to-hit rolls, a +2 agility modifier allows you to add +1 to your AC, and a +5 agility mod allows you to add +2 to your AC.