Random Idea: Stat-Gated Effects
Off-builds are a dying breed. Whereas at the beginning of League, champions were intentionally designed with the possibility of going for AD, AP or even tank builds, nowadays kits are designed with only one of those stat lines in mind. The main reason cited for this is that it is extremely difficult to balance a champion around building in two completely different ways, and being equally balanced at both, since changes designed to affect one build will also affect the other. In addition, because the differences between builds usually boils down to stat scalings on a champion's kit, off-builds frequently end up becoming hyper-focused or simply weaker versions of main builds. AP Miss Fortune, for example, has better damage on her E and a killer Q when coupled with Lich Bane, but otherwise does everything AD MF does, only weaker. Even outside of the AP/AD divide, issues frequently arise when AP-scaling supports want to also be viable in solo positions, and cannot adequately compete because their bases and scalings have been adjusted around bot lane support builds. Giving more power to one build, but none to the other, is effectively impossible in the current framework, precisely because mere ratios do not allow for it.
Enter stat-based milestones.
What do I mean by this? Well, the idea is to give champions certain bonuses that activate only when they build enough of a certain stat. To pick just a random example, Miss Fortune's Love Tap could splash for AoE damage if she has 200 or more AP: because this would require committing to a stat line, it would give power to one build (in this case AP MF), but not the other. The opposite could be done as well: for example, Fizz could be made to lose the untargetablity and damage on his E if he builds more than 50% of his base health in bonus health, and this method could allow assassins to have more forgiving bases without running the risk of succeeding too well with tanky builds. Taken far enough, this could allow champion kits to do really different things depending on how you build them, allowing for real variation in playstyles.
The main potential issue with this, imo, would be complexity, in that it might involve memorizing different effects depending on which items are being built, though at the end of it there are essentially only about three different main stats that can be committed to: AD, AP and health/resists. This would also require some additional design work to develop these effects and thereby explore new ways of playing the same champion, though ultimately League should also likely be doing that already, as there are usually no more than two ways, and often just one, to play a champion. If done correctly, these kit mutations according to stats could be the start to many more off-builds, particularly since those off-builds could be added over time via these stat-gated changes, without having to rework the base kit.
What do y'all think of this? I've checked the Boards history to see if this was posted already, and haven't seen anything like it come up, though I could very well be mistaken. For those who do play off-builds or look to innovate on champion kits, how do you think this idea would affect your custom builds and playstyles?