I would like to see a DPS only system. You can have a 100 different ways of doing damage and moving around on the battlefield and blocking damage but straight healing is gone, and tanking is done entirely through positioning and creating barriers between enemies and targets. The barrier could be a summoned wall, quicksand, a wall of shields, traps, a choke point or the swing radius of someone's weapon.
You could intercept, tackle, knockdown, bash, stun, snare, root, freeze, block, dodge, kill, and otherwise impede enemies from reaching their goal. All those mechanics combined fill the role of the tank. Just sitting there begging to get hit, that will get anyone killed.
I also would like to see a system where everyone effectively has 1 hp. A character has a single resource pool, stamina. It's amount and rate of recharge depend on the constitution or just stamina stat. Every swing, dash, roll, jump and combat action drains stamina. As more stamina is used within a short period of time, the rate of recovery begins to slow down. Until it is just barely trickling back in. At this point the character is exhausted and needs to not take any strenuous activity for short a while (Think Old EQ mana regen, just sit and take a break).If a character loses all of their stamina, they lose consciousness. At that point they are vulnerable to being attacked and killed.
Skill levels and stats will determine the rate at which stamina is consumed. Wielding a heavy sword will drain a lot of stamina from a weak character, but not so much from one with high strength. Being proficient with two handed swords will also reduce stamina drain per swing.
Magic will also consume stamina, except instead of strength, intelligence will be used to determine how much a spell consumes. Mastery of spell levels/schools will greatly effect this rate. At first spells will have to be channeled. Eventually, as skill levels rise, spells will be able to be cast instantly. While a spell is being channeled it is burning down a players stamina. If a player does not have enough stamina or the burn rate is too great, they will lose consciousness before the spell is cast. The higher the level spell the longer the initial channel time and the higher the burn rate.
So a novice mage could in fact attempt to cast a high level spell (if they got their hands on the spell scroll), but the cast time will be very long and the stamina burn rate will be very high. However, multiple casters could link together so that the stamina burn is distributed among the group of them and greatly lessens the burden on any one player. Some extreme level spells would pretty much only be able to be cast this way.
Once a mage has thoroughly mastered a certain spell or school or level or spells (however they wind up getting categorized) The channel time will become instant for that spell and will simply burn an amount of stamina as if it were a sword swing or other action.
Combat damage wont really exist with everyone effectively having 1hp. Instead combat will revolve heavily on status ailments. When someone gets hit by a weapon or a spell, they will suffer a status ailment appropriate for that type of damage. A slashing weapon would cause a laceration with bleed damage (stamina drain over time), A blunt weapon could cause a broken bone (limb crippled and unusable as well as a large single hit to stamina) a fire spell could cause a burn, (reduction in maximum stamina and possible crippling)
Also the location of the attack could have it's own effects. A blow to the head could cause blindness (everything goes black except for UI elements), a concussion (ability to doge and to hit reduced), a stun (a short freeze to player actions).
A hit to the chest might knock the wind out of someone (reduced stamina regen for a while), collapse a lung (maximum stamina reduction and large reduction to regen), crack a rib (reduced regen and small penalties to hit and dodge rates.)
A hit to the legs could result in a knockdown, reduced movement speed, sliced artery (Huge stamina drain).
All hits will result in some ailment ranging from minor bruising all the way up to decapitation. The severity of a hit is determined by how well armored the target is, and how skillful and strong the attack was. Essentially the ailments would be listed on a table. A character with a high weapon skill, and a sharp, heavy, strong or otherwise effective weapon, and a high determining statistic such as strength or int will put their hits high on this table. The targets defensive stats such as armor, stamina, dodge rates, chance to deflect or parry will try to reduce this value.
If any player is struck in the head or chest while unconscious they are killed instantly.
All healing and recovery would be done strictly out of combat. The in-combat status can fade if a character has not attacked or been attacked for a period of time. Picking up and carrying unconscious players would be possible with their consent. If a group could maintain a front line, they could cycle players in and out as they became injured during a lengthy fight or siege. Healing and injury recovery would take a while, almost like rez sickness. Dying would always cause a lengthy rez sickness ailment that lasts longer than any recovery time.
However planning a triage center would not be very effective for most sized groups. There wouldn't be enough people fighting to effectively finish the encounter. Only Large battles involving armies would really benefit from this tactic.
That's all for now.