Putting Magic in your Magick.

Hit Points as a Power and Active Defenses

On the Player Character sheet you now record the Defenses without the base 10 value and the player rolls d20 instead and adds… it is compared to an Attack value which is static 10 + mods for the NPC’s.(it is supposed to be 12 if you want to maintain the odds but I have low player count and sneak things like this in --- shush dont tell). (an alternative to those wedded to Character builder is just use 22+ for the NPC attack value)

The DM describes an attack (and the nature of its primary effects generally and what defense it is against).. Basically you describe the start of the attack without its full... culmination just like a player might do.

The player should then describe how this attack against their character is minimized by luck and energy and skill! The difference between the description for a failed defense (unless that hit reduces you below 0 hp) and a successful one … is pretty much how desparate or last second it normally seems and/or how much apparent energy/luck it takes to accomplish, even a successful defense could be described many ways... ranging from the bad guy doing really poorly, the character doing really well with the ability associated with defense, or the character getting wierdly lucky if that is the pc’s style. The lucky hero, the tough hero, magical hero and skilled heros the archetype often inspires the nature of there defense. Note A magical hero can even describe his defensive actions and how they minimize his injuries in terms of his magic, just make it fit the theme of your character... exploit what you do with your at-wills perhaps.

Which of the attributes you use for your defensive actions may also affect how you describe it,(is it Intelligence representing forethought and predicting your enemies actions so reacting almost before they act or is it dexterity defense without a thought nerves of lightning) but they dont always have to. ie. which attribute is luck? and which matters if you just feel like describing a quirky sort of jinx like failure on the enemies attacks? A d20 is a pretty hefty impact and can overshadow your defensive values. Did you luck out and the armor take more of the hit than it seemed (heavy armor?)

It becomes a descriptive choice. A hit that reduces the character below zero hp might best be described by the DM who then includes after effects, this is the point were a true wound mechanic might come in to play.

Voluntary Wounding

Somethin like this I saw elaborated first on in Enworld.org It fits in with the above real well because it involves the player voluntarily accepting a long term wound for their character. The wound causes periodic impairing effects that the character can overcome with saving throws normally. This imparing effect recurs when the pc makes a really poor roll on an attack or (and maybe a defense) this is called aggravating the injury. Say a roll of 1-2 on your attack, aggravates one of your wound conditions DM's choice. For instance a recurring Slow effect associated with a leg injury etc. These of course involve letting the DM describe the attack and the wound. In exchange the character keeps the hit points and still have a buffer they can apply against future injury.

The wound will only go away using time or ritual magic.

More uses for hitpoints.

If you noticed some of the ways you minimise and attack with hit points indeed sounds like succeeding on making a saving throw? Well character luck and resolve/energy has indeed always been described as components of hit points and those seem to be what your character is using to make that save! The following rule demonstrates and tightens that connection. Effectively Hit points/Healing Surges and Saving throw overlap, I am thinking hit points ought to have a conversion between them and saving throws ... There are certain effects that really shouldn't happen except to a hero who is completely "out of their luck" and or out of energy, ie out of hit points. Forced movement into the bottomless pit is one such situation... there are probably other save or die situations lingering yet.

Hit Points as Luck

A player may spend a healing surge (or a healing surge worth of hit points) to re-roll a failed saving throw or in some cases (at DM's discretion autosave) a saving throw or to prevent complete incapacitation from a spell or power, for instance when they have no one to guard their incapacitated self. Not every save or situation qualifies but for a save who's failure would result in an effective instant death it seems allowing a auto save is reasonable for less absolute situations it could still be reasonable to allow a re-roll.

Hitpoints as Energy and resolve

the same hitpoints or healing surges players spend on staving off imparement and death of their character might be used to allow re-use of a power. This latter might limited to making a power reliable? or something of that sort or it might be only once per encounter. To some degree the balance of this option depends on how much of a precious commodity healing surges are in your game and whether they are likely to induce the 15 minute game day phenomena, some players find they almost never run out others are on the edge and some only have battle encounters every so often and pc's using their full allotment of surges in one fight is not really a problem.