The Articulate Plane
Most weapons in the Articulate Plane can be augmented with special gems that augment them with magical powers. While the gems are rare and expensive, any self-respecting blacksmith always puts at least one gem slot into any weapon he makes.
Gems cannot be created or removed without special rituals, but any settlement of decent size should have a ritualist who can perform this task for a small fee.
Here’s how that works mechanically: every item that takes up a body slot, including every weapon that is not ammunition, automatically comes with a single gem slot. Adding slots costs the full cost of weapon.
Most magical properties of an item (frost, vorpal, etc) will probably come in the form of a gem. Binding the gem into an open slot is a minor action and takes effect instantly.
Action points can also be used as Immediate Reactions to give +5 to any d20 roll (after seeing the result). If you have a creative idea for the use of an action point, just ask – I’ll probably say yes.
Skill challenges are replaced by unstructured check-heavy roleplaying. After roleplaying of any kind, XP will be awarded.
Legacy points will be meted out to reward good metagame player behavior. These points – which will be handed out in the form of poker chips – can be spent to add +1 to any d20 roll or to re-roll a d20 result of 1.
You can collect legacy points in various ways:
Completing your turn in an encounter very expediently: 1 point.
Having a really clever idea in a skill challenge: 1 point.
Brilliant roleplaying: 1 point.
Writing an adventure log entry: 2 points.
The yuan-ti is now a playable race.