There’s definitely something to be said for simplifying the skill system from 3.x, so we’re going to port over some of their ideas. In particular, the idea of combining several existing skills into one (a very common house rule in 3.x games and variants).

I’ve combined even more skills than they have, and then broken a couple down into “specialties,” which I’ll explain in a bit.

In parts I've tried to maintain the formatting of the 3.x PHB, but I've only included things that have changed in some way. All other rules work as stated in 3.x.

Skills Summary

Adventurers have need of a great variety of skills throughout their career, no matter which path they choose to follow.

Getting Skills: A character gains 4 skill points per level gained, plus one skill point per point of Intelligence bonus. Humans gain an extra skill point per level. At 1st level, the character gains 16 plus four times his Intelligence modifier in skill points; humans gain 4 extra.

There are no class and cross-class skills. Any character can choose to specialize in any skill he or she wishes. Each character gains access to a number of heritage skills depending on which class he chooses at first level. Regardless of whether a skill is a heritage skill or not, spending one skill point gains you one rank in that skill. Your maximum rank in any skill is character level +3.

Using Skills: No change.

Skill Ranks: All skills can be used untrained, but there is a DC 10 cap on the result of any Int-based skill check for which a character neither has ranks nor designated as a heritage skill.

Acquiring Skills at 1st Level

Follow these steps to pick skills for your 1st-level character.

1. Determine the number of skill points your character gets. All characters get 16 skill points at first level, plus 4 skill points per point of Intelligence bonus.

All characters get at least 16 skill points at 1st level, even if he or she has an Intelligence penalty.

Some characters also get extra skill points based on their race.

2. Choose your background skills. Each character may choose one Knowledge skill and either one Craft or one Profession skill: these skills are treated as heritage skills.
3. Choose your heritage skills. Each character gets a number of heritage skills based on his or her class.
4. Spend your skill points. Each point you spend on a skill gives you one rank in that skill.

Skills at Higher Levels

When your character gains a new level, follow these steps to gain new skills and improve existing ones.

1. Each character gets 4 + Intelligence modifer new skill points at each level (min. 1). Your race might give you more.
2. Spend your skill points on any skill that you haven’t maxed out the ranks in.
3. Adjust your heritage skill bonuses if you’ve just attained an even-numbered level.

Heritage Skills

Every character has a pre-adventuring background that includes education and training in a variety of skills, some useful to his chosen profession and others less so. Sometimes this training is a perfect match, making the character a paragon in his field. This training is reflected in a character’s heritage skills.

A character gets a number of heritage skills at first level, determined by his class.

Class	# of Heritage Skills
Barbarian	3
Bard	4
Cleric	2
Druid	2
Fighter	2
Monk	4
Paladin	2
Ranger	4
Rogue	6
Sorcerer	3
Wizard	2

You must choose your heritage skills at 1st level, and they never change.

Benefit: Designating a skill as a heritage skill grants you a +2 bonus on all checks made with that skill. This bonus increases by 1 for every two character levels you achieve (+3 at 2nd level, +4 at 4th level, etc.).

Skill Specialties

Some skills in this system have combined the functions of multiple previous skills. If you choose one of these skills as a heritage skill, you must select a sub-skill on which you receive the heritage bonus. These skills and their sub-skills are:

Acrobatics (Balance, Escape Artist, Tumble)
Athletics (Climb, Jump, Swim)
Interaction (Bluff, Diplomacy, Intimidate)
Lore (Decipher Script, Use Magic Device)
Perception* (Listen, Search, Spot)
Stealth (Hide, Move Silently)
Thievery** (Disable Device, Open Lock, Pick Pocket, Sleight of Hand)
Trickery (Disguise, Forgery)

* If you designate Perception as a heritage skill, you can choose to gain the bonus on Search checks or Listen and Spot checks.
** If you designate Thievery as a heritage skill, you can choose to gain the bonus on either Disable Device and Open Lock checks or Pick Pocket and Sleight of Hand checks.

You may designate a single skill as a heritage skill more than once in order to gain the bonus in additional sub-skills. (For example, a fighter could designate Perception as both of his heritage skills, gaining the bonus on Listen, Search, and Spot checks.)

Skill List

Appraise (Int)
Acrobatics (Dex)
Athletics (Str)
Concentration (Con)
Craft (Int)
Gather Information (Cha)
Heal (Wis)
Interaction (Cha)
Knowledge (Int)
Lore (Int)
Perception (Wis)
Perform (Cha)
Profession (Wis)
Ride (Dex)
Sense Motive (Wis)
Stealth (Dex)
Thievery (Dex)
Trickery (Int)
Use Rope (Dex)

Missing Skills
Speak Language is gone because I’m importing 4e’s feat-based version.
Spellcraft is part of Knowledge (arcana)
Handle Animal is now a Profession.
Survival is now covered by Knowledge (nature)

Ok, so there are probably lots of comments and questions. Some of my immediate questions are outlined in the To-Do List. Feel free to add things there, or comment in the forum thread below!