Adaptive Force could make tank items viable on other frontline classes.

inb4 THERE'STOOMUCHDAMAGEINTHISGAMEALREADYAAAA

3 out of 5 champions per ranked match are building nothing but raw and overall offensive damage items - 101% of statistics are made up but I dare someone to wildly disprove me on this in what is to be Preseason 10 of the further continued wake left by Runes Reforged. Adaptive Force upping the gold value of underwhelming defensive items would be a way to help melees fighters, bruisers and even tanks themselves to keep relevant damage and waveclear while also enabling them as a frontline. Meanwhile this would be a positive, non-net zero change for tanks; while their ablities don't have incredible scaling they're still very relevant and having some AF would help many of them manage lanes better without buying offensive items.

Worth mentioning is that a defensive item reworked to include ~500 gold worth of Adaptive Force won't be nearly enough to enable assassins to stack them again; ever since RR min-maxing burst is extremely valuable to that class and one-and-a-half Longswords inserted into ex-tank items won't change that. Mages will also deservedly have trouble fitting AF items into their core since they don't have mana or tons of CDR; still, for even the most assertive of classes it would be a breath of fresh air for them if they could access defense after their core without investing in a purely defensive item or being forced to buy or every single time.

Unlike myself, however, LeagueOfGraphs does not make up statistics as far as I am aware. These are the buy rates for tank items in Platinum+ games globally: 3.4% 2.6% 1.6% 1.6% 1.4% 1.0%

Not very impressive, right? At least frontlines are still buying SV? Let's see their buy rates in Master+: 1.9% 1.1% 1.0% 0.9% 0.7% 0.7%

Despite tanks being played somewhat less often in the highest echelons of ranked, the difference in buy rates between just two tiers is just ludicrous. The winningest players are buying significantly fewer defensive items than everyone else. It's hard to look at these statistics and think that any of these items are in a good spot right now. Toto, I've got a feeling we're no longer in Season 4 anymore.

Reworked defensive items with Adaptive Force would gain 200~300 gold value by gaining 20-30 Adaptive Force at the cost of half of the AF's value in either their defensive stats or finished item price. These items would no longer be considered strictly "tank" items but frontline items that a number of classes can consider investing in at any point in their core builds. The items would be less effective at offering sheer defense but would become ways for frontlines to become tanky while retaining some pushing power and relevance towards whittling down targets without finishing a pure damage item.

So that champions desiring Adaptive Force in lane would have earlier access to the stat, finished defensive items with AF could build from a basic item that gives Adaptive Force, like:

Dauntless Orb - 410g 20 Adaptive Force (20 AP or 12 AD, depending on type of damage purchased then ability scaling)

Alternatively AF could just be a passive bonus for finishing a defensive item, but a major flaw in defensive items for non-tanks is their hefty completion cost and those items building out of something like this as well would alleviate that trememdously.

Defensive items that Adaptive Force needs to avoid being on:

• 20% CDR items: everyone would abuse it, offensively or otherwise.
• support items: would ruin the item for supports. Shurelya's Reverie will become the least popular item once Ohmwrecker and Zz'rot are removed - ever wonder why? Who here joining us from season 8 onwards even knew this item existed?
• pure armor+MR items: would make the item readily available to marksmen and hypercarries that already build lifesteal and have protection from their supports, making their combination of damage, resistances and heals/shields completely overbearing for the enemy team.

Adaptive Force contenders plus ways to comfortably implement AF into them: Randuin's: the price should be increased rather than its defensive stats reduced, since it is effective against crit and should remain a commitment towards that.
DMP: decrease armor to 50; easy!
Warmog's: increased cost and perhaps a little less HP. That much health on an item that inexpensive is too gimmicky and unwieldy for most champions since even before RR; also its out-of-combat regen max HP requirement should be drastically lowered so that more frontline champions have reasonable access to it. Spirit Visage: Spectre's Cowl could easily be reworked to grant Adaptive Force instead of HP as no one buys it in lane anymore anyway! More AD/AP for champions with self-healing will make SV much more appealing to them. They won't miss the HP that much whether in or out of lane, and tanks will still vie for it despite it granting less HP. Sunfire: Increase the cost; losing defensive stats and gaining AF would make it more of an offensive item than a defensive one. Thornmail: Same as Sunfire: increase the cost to keep the defensive qualities of the item relevant. Adaptive Helm - Similar to Randuin's, its price should be increased instead of reduced defensive stats because countering one particular type of damage should have a pricetag that reflects that commitment.

To compensate for losing defensive value on many of their core items, tanks deserve an actual strong MR defense item - not SV, not Adaptive Helm - a strong, purely defensive, cost-effective item that tanks could call their own. Something that would make tanks a real force of nature, y'know? Just saying, Riot.

I worked a long time on this essay of a post so it'd be appreciated if you read before you tried poking holes or asking rhetorical questions; regardless, thanks for posting. Thanks for reading as well!