As I noted when I originally posted on the subject of skills in OD&D, I do believe in having some kind of simple, consistent skill system in play for the same reason that I believe in having a simple, consistent system for resolving combat. I believe that only having some kind of skills system makes the thief class consistent with the way the rest of the game is played and avoids the "have to have a thief to disarm the traps" syndrome. I believe that a good system should neither require certain skills in order to have a chance of success at an action that is physically possible, but should only provide a minor bonus to the chance to succeed in the action. I also believe that a character's stats should provide a significant influence on the outcome--a character with a natural 18 in dexterity should have more than a 20% improvement in his chances to hide over one with a 10. And finally, I believe that skilled play should count most of all.
When I first unveiled my little attempt at creating a skills system last year, a lot of people were confused, and understandably so. I frankly didn't present it very well, lumping several concepts together into a single, confusing chart. That was definitely an error on my part, especially since I didn't explain exactly how I came to my design decisions. So here I thought I'd talk about some of the alternatives suggested in dealing with non-combat, mundane task resolution:
No Skills; Referee Fiat
Most other options suggested for OD&D involve using an existing mechanic in a new way.
Saving Throws as Skills
This system has a couple of advantages: First, it doesn't really require the creation of a new mechanic other than some thought into how to ad hoc modifiers for difficulty. And since the saving throw target number automatically decreases as the character rises in level, it can serve to reflect a generally rising competance in all areas as the character grows. The major disadvantage--although your mileage may vary on this one--is that it minimalizes the role of the characters ability scores in determining success or failure; depending on how much of a bonus the referee gives for high stats, a character with an 18 in the relevant score may only have a 10%, 15%, or 20% increase in their chances for success over one with an average score.
Use the Reaction Roll Table
This is actually not a bad system at all for general task resolution, and I've adopted it for my own campaign as a sort of "heck if I know" table. A character wants to try to shove a heavy boulder over to start a rock-slide; heck if I know how to calculate that, so roll 2d6 and add your strength bonus. A cleric wants to know if they've come across a certain symbol in their studies? Heck if I know; roll and add your INT modifier.
But while this system makes for a handy mechanic for those situations when you just want a general idea of success, it starts to fall apart if you try to implement any special bonuses for background, learned skills, etc. due to the aforementioned power of even modest bonuses.
Ramping Up the Dice
This is the system that I've implemented and described back in Skills: The Middle Road. It basically developed when I noted how often the d6 is used to resolve action in play (hardly a surprise given D&Ds pre-polyhedral Chainmail origins). For example, surprise is determined on a d6, with a roll of 5-6 indicating surprise. Getting lost is rolled on a d6. A roll of 1 or 2 on a d6 indicates successful foraging for food. And so on.
From there, it was a simple step to invert some of the rolls as given in a simple fashion: High is always good, low bad. And from there, it wasn't hard to imagine characters with relevant backgrounds and/or learned skills using something other than the ol' d6 to determine success. Instead of needing to roll a 1 or 2 on a d6 to find enough food, one had to roll a 5 or better--only it didn't have to be a d6; it could be on a d8, d10, or d12, depending on the skill of the character.
Ability modifiers can and often do, of course, play a significant role. The question is whether a single ability score in a single character would be the deciding factor in the success or failure of the action. So, for example, Dexterity will modify an attempt by a single character to actively hide, but not the surprise roll (which is rolled for the party).
Clever use of equipment also makes a much greater difference to characters under this system. In D&D3 a +2 circumstance bonus doesn't go far; under this system, a +1 bonus for cleverly pouring water on the floor to look for a pit trap, using a climbing harness to scale a wall, or using a spear to aid in balance while walking across a narrow parapet makes a considerable difference to the character in question. Therefore, it actually makes sense for a party on a scouting mission to carry minimal equipment and use only light armor and to move at 2/3 their normal pace, granting a total of +2 to the surprise check--especially since, in my game, winning the surprise roll means that you detect the other party before they detect you, giving you a chance to avoid them altogether. Even without the whole party consisting of elves, halflings, and thieves, its a significant advantage.
I've deliberately avoided target numbers (Difficulty Levels, or DLs) higher than 6 in most cases, and in cases where they do run higher I've tried to make sure that there are ways for even low-level, unskilled characters to have a chance at achieving success through careful play. For example, the DL for hiding in the shadows with no actual cover in bright sunlight when someone looks directly at you is something like a 10. A halfling might be able to pull it off (in the wilderness, at least), or a high-level thief. Everyone else had better find some cover or climb a tree or something to get that target number down.
I've come up with a list of probable PC actions, the appropriate ability scores and backgrounds, if any, and some DLs to use for comparison, but it lends itself to easy ad hoc rulings, and it doesn't seem to be confusing my younger players at all. Mostly I just tell them what die to roll and which ability modifier to use, and they're happy with that.
Is it "Old-School"? I really don't know--and I really don't care anymore. It's fun, and that's all that really matters.