If there ever was a video game that would make an excellent transition to a Collectible Miniatures media, this would be it.
I think a rules system would be easy to map out, and you could probably even psuedo-copy the one from Heroclix without too much legal drama if you didn't want to put too much thought into it. However if you did want to put a lot of thought into it, there is a wealth of things you could do with a rules system, and it would be interesting to see which pieces stood up best in a different format.
A booster pack would cost $9.99 and come with 4 randomly assorted heroes. To increase collectibility, rarer pieces would have skins, with some skins even improving or modifying the stats of the original piece. There would be 4 flavors of each hero: Common, Uncommon, Rare, and Skinned, as indicated by a different colored ring around the base of the champion.
Each champion has a value assigned to them, at the three different tiers of rarity, which will be added and totalled for determining team value, which you may then use to create your team.
There are different maps, based upon real in game maps, tiled, with the objective of either wiping out the enemy team entirely, or destroying their base. The maps would have set values of what team value could be played upon it. For simplicity's sake, let's assign 500 to Summoner's Rift and 300 to Twisted Treeline as 2 base maps.
The champions are seated upon circular disks which can rotate, as in any standard miniatures game, with numeric values for their Movement, Attack, Defense, and Remaining Hit Points. These values change as the disk is rotated. The disk is rotated when the unit takes damage, or uses an ability which costs a turn of the disk, afterwards referred to as a click.
With each click, the values upon the disk change, typically making the unit weaker. If a unit foregoes an entire turn, or has the ability to, they may turn the dial backwards, restoring clicks. Beneath the numbers, are colored squares keying special abilities the character has with that click. When that click has passed, if the colored square is no longer highlighting the number, that ability is lost. When no more numbers appear on the dial, the unit is dead, and removed from the game.
Sound interesting yet? If there's enough interest, I'll make some more rules and perhaps go as far as to shave and repaint some old miniatures of mine to resemble LoL characters.