Well the thing is D&D/d20- is not really  player friendly so much as it's highly visible and is like the first system players are exposed to.

Anyway I don't really think a zelda adaptation is something that benefits from a lot of mechanics.  If you're trying to do a system for zelda there's like a handful of simpler systems that could be used depending on taste. Since you wanna go with having stats corresponding to the 3 tri-force pieces I'd say use tri-stat. 

Tri-stat's core is as its name suggests, you got three stats which can be renamed to the corresponding tri-force pieces and then you roll 2d6 [b]under[/b] your associated stat with modifiers coming from like difficulty which can raise or lower the TN and skills which raise the TN. Snake-eyes are a crit success and converse is true with boxcars.

Now for skills, instead of a big sprawling list of them, let's go with something compact and narrative friendly. You get a handful of backgrounds which are like snippets of backstory which are then justified to being applied to a stat roll. Anyway, these backgrounds have like a certain value which is added to the TN if appropriate for a roll. Now a 4 is considered average for a human, and a 2d6's average result is a 7 so background should be ranked accordingly with the strongest background being something that can make that 7 a passing roll most of the time.