TFT has the worst A.I. that I've ever seen.
Disclaimer I am aware that TFT claims to be in BETA but as we've seen in recent years in gaming, that term has lost its meaning a long time ago. I think it's more fair to call this a rushed Alpha because the skeleton of the game is the only thing that works. balance is off the hook in terms of item acquisition, hero get and the reason for this thread, the A.I..
I've played a total of 8 games I believe so it's fair to say that I probably haven't seen all the funky stuff yet but I've managed a few top4's and a 1st place, so I am not completely inept.
My experiences with funky A.I..
Blitzcrank (Hooks furthest away target and knocks up)
Starts the combat by hooking the target in (usually a Carry unit that's placed in the back unless a smart player placed a decoy). Blitzcrank then proceeds to LEAVE the target alone to hit another target 3 tiles away with auto hit. essentially giving a potential CARRY unit the free roam on your backline like a assassin unit would. Blitzcrank proceeds to fight a 1v2 vs 2 melee units. auto its primary target to 25% hp. reaches full mana THEN TURNS AROUND and hooks the other unit in melee combat and starts to auto hitting that, instead of finishing its original target.
Graves (Shoots a cone attack 1 - 3 - 3 tile cone respectively from innitial position)
Graves will often stutter in his attacks and walk back and forth between 2 tiles even though no units are dying causing a target switch. Graves doesn't prioritize full functionality and will often hit a target standing alone rather than position to get the optimal out of his cone attack, basicly nulling his ability which makes him a USELESS "ranged" melee unit with a existential crisis.
In general, units will without being the victim of a stun, seek to the bottom of the fighting arena and stop attacking, not just animation on attacks bugging out and proceed to deal dmg etc. but actually completely stop their attacks.
Several assassin units will more often than not, Jump the backline, then proceed to IGNORE the low health (of total health pool vs other units) and move to the back of the enemy frontline and beat on tanky units.
Leona will at times choose to use Stun ability on a single unit in the far back rather than the 3 stacked Melee champions. (Aoe attacks should by default target MULTIPLE units if available)
Garen will start spinning with only 1 target in range instead of moving to the tile next to him with 3 units within range. (^see previous note)
Varus will line attack a single unit instead of the 2 units standing in line.
Kindrid will Ult without allies nearby.
Shyvana and Gnar will more often than not push enemies DEEPER into your units giving AOE / cleave units better options to hit your entire party.
And this is as far what I've experienced in my few amount of games.
This horrible A.I. Paired with HORRIBLE RNG outcomes makes this game absolutely terrible and it could quickly turn it into a game experience where you will play the first 3 stages searching for functional A.I. heros and pairing with potential items acquired, and if not, quit / surrender the round and start a new, potentially leaving all lobbies with few remaining players.