Awareness Based Combat

One of my favourite computer games, Phantom Doctrine, has an interesting combat system, using two different resources--characters have hit points (HP) and awareness (AP).  When you get hit, you lose AP first, this represents dodging, then you lose HP.  But AP is also used to power your attacks, and it regenerates every turn.

This would be a lot of book-keeping for a TTRPG, but it could be accomplished with computer aid, using custom scripts in Excel or Google sheets, or with counters.

This system also takes care of surprise, by saying you have no AP most of the time, and must build it up when combat starts.  People in slightly heightened situations, creeping around in a dungeon for instance, might maintain half AP.

Spells and special attacks would cost AP, and maintaining a spell would prevent regeneration.

With all this in mind, we could create a system:

Values

Using weapon damage dice from AD&D 2e, appropriate values for HP and AP would probably be around 5-6 and 10-12 respectively.

Regeneration

At the start of their turn, a creature regenerates 3 AP.

By spending an action focusing, they regenerate an additional 3 AP.

Attacking

Attacking costs 3 AP.  Training lowers this to 2 AP for a chosen class of weapons.  There is no attack roll, just roll for damage.

Defense

Armour applies damage reduction to HP damage only.

Shields

Shields provide damage reduction of 4 to AP damage only, but cost 4 AP to use, i.e. they prevent all the damage between 4 and 8 AP.  Training increases the DR by 1 and reduces the cost by 1, standing in a shield wall does the same.

If you don’t have enough AP to use your shield, the damage will roll over to HP without using the shield’s DR

Manœuvres

Mighty Blow--5pts

When attacking with a martial weapon, do max damage as per weapon, plus strength bonus

Backstab--5pts

When attacking an opponent with no awareness, with a accurate melee weapon, do 5 damage, plus intelligence bonus

Headshot--5pts

When attacking with an accurate missile weapon, do max damage as per weapon, plus dexterity bonus

KO--Target’s HP + AP + 1

Roll 1d8, on a 1 the target dies, otherwise they are rendered unconscious

Murder--Target’s HP + AP + 1

The target dies.

Blood Strike--5pts

Deal 1 damage to your opponent’s Stamina, even if they have Awareness

Parry--3pts

With a parrying weapon (sword, quarterstaff, etc.), as trained shield

Disarm--6pts

When fighting in single combat, with a parrying weapon, if your opponent has no more than 2 awareness, disarm them

Suppressing fire--3pts, group only

Deal 3 AP damage, and prevent AP regeneration.  You can suppress a closely packed group of 1 less enemy than you are working with.  It is not possible to suppress only enemies if they are engaged in melee with your allies, you suppress your allies as well.

Magic Missile--1pt + 2 per level

Deals 1d6 damage per level of the spell

There’s a lot of scope here to add martial arts, extra complexity, training or abilities that increase your AP or regen.  You might also get rid of random weapon damage, just have some flat values.  This would give you a little more flexibility around HP and AP values, you could make HP the character's Stamina attribute for instance, and make their AP either a skill or maybe Perception + Agility + X per level.