Back when I was running 4E (I pretty much only run 13th Age now), I ran one-shots using two different sets of houserules:
Houserule Set A:
- Whenever a character takes an extended rest, he regains 1d4 healing surges (1d4+1 at paragon and 1d4+2 at epic) and can make a saving throw for each expended daily power. On a success, the daily power refreshes.
- Achieving a milestone bestows the same benefits as taking an extended rest. DM has final say on when a milestone has been reached.
- At the conclusion of an adventure or a major quest, all your hit points, healing surges, daily powers, and action points reset.
I found these houserules lengthened the adventuring day while simultaneously ensuring those "only one fight" days had an impact on long-term resources. Players also didn't hoard dailies as much when there was a 50% chance they'd get them back every 2 encounters.
Houserule Set B:
- Characters do not gain any feats or encounter powers beyond those automatically granted as class features or racial traits.
- Characters can use each of their daily powers once per encounter.
- Characters gain a bonus to at-will damage equal to their level and to daily damage equal to twice their level.
- Characters do not have healing surges. When they take a short rest, their hit points are automatically restored to full.
- Characters do not have action points.
- Characters can use second wind as a minor action and it restores their bloodied value in hit points.
- When a character is affected by a power or effect that references a healing surge, he only heals a number of hit points equal to his Con mod + his level (defenders heal Con mod + twice their level).
- Whenever a character would gain an encounter attack power, he gains +1d6 damage to all critical hits (stacks with those provided by magic items or inherent bonuses).
This set of rules was obviously heavily inspired by Gamma World. My goal was both to simplify and speed up 4E combat while making it a bit deadlier. Mission accomplished: using these rules, my group cleared the Red Box adventure within 2 hours.
Just some food for thought.
