I’ve had players who took it for granted that it was always better to wear armour than not, and assume they’ll always have it on, whether walking through town, making a voyage by ship (when falling overboard should obviously be fatal), or sleeping. Putting aside for a moment that falling asleep in armour is highly improbable and showing up in a crowded market decked out in military gear would have the local guard surrounding and interrogating the party in no time, let’s focus on the relative merits and demerits of various types of armour in the context for which they’re meant: Combat.
The following benefits and drawbacks of armour in combat are meant to be included in the upcoming revised version of House Rules for the Shropesyre Campaign. The list below describes the range of protection likely to be encountered throughout the British Isles; other items may be encountered if the party travels to other regions, and specific attributes of such can be included later. As AC is already tied to increases in level rather than types of armour, the latter are considered to reduce HP of damage taken by a percentage according to their basic type.
Here is the breakdown for shields, armour, and other protective items.
Shields: Use Hit Location die. HP damage reductions apply only to hits to torso or shield arm.
Small wooden shield (buckler): 25% reduction, rounded down.
Small metal shield: 25% reduction, rounded up.
Large metal shield: 50% reduction, rounded down.
Full body shield: Generally, the only body parts exposed during melee are the sword arm and part of the face necessary to see: Hits to the sword arm are treated as normal, while the face is considered to have an AC bonus of 4 for 50% concealment. Hits to any other location are automatically negated.
Armour: If used in conjunction with a shield, the following apply only to hits taken to areas other than torso or shield arm. For hits to either of these two areas, damage is first reduced by the shield and then again by the armour itself.
Leather or hide armour: 10% damage reduction to all covered areas, rounded up.
Studded leather armour: 20% damage reduction to all covered areas, rounded up.
Chain mail: 50% damage reduction, rounded down.
Plate mail: 60% damage reduction, rounded up.
Full plate (rare item, not normally available for purchase in England): 75% damage reduction, rounded up.
Shields and armour used together offer combined benefits. Full plate armour used in conjunction with a shield offer total protection against blows except in the case of critical hits. A critical hit to the shield arm is considered to break the shield or otherwise render it useless. Furthermore, any critical hits dealing 12 or more points of damage to any location are considered to knock the combatant over. Falling in plate mail armour from a standing position causes 1d3 HP of damage. Falling from horseback in plate armour causes this 1d3 HP of damage in addition to the 1d6 HP of damage ordinarily accorded to such a fall.
Additionally, because armour restricts agility in combat, the following penalties to THAC0 will be applied when any of these types of armour are worn (points by which THAC0 is raised):
Leather or hide: None
Studded leather: +1
Chain mail: +2
Plate mail: +3
Full plate: +4
Finally, wearing or carrying armour while traveling will considerably slow the character down due to additional encumbrance. However, carrying it would be the better choice unless combat seems imminent: Tentatively, I refer to a chart for HP of discomfort damage the heavier metal types of armour cause after a certain period. The reality is that after a few drinks and a number of variables to hold in my head during melee, I tend to forget all about it—but, be warned, I’m not likely to forget to roll for fungal infections and anal fistula if your character is covered in mud, has been sweating profusely, or got caught in the downpour.