Stackosaurus Rex

• On Smolder, remove Stackosaurus Rex after reaching 225 stacks; beyond that point, stacks add little to his scaling, and AD is more valuable.³
• With Kindred, pair Stackosaurus Rex with Back to Basics or Jeweled Gauntlet and items such as Shadowflame or Liandry’s to increase the damage of W, which rises with each stack.⁴
• Pair Stackosaurus Rex with Heartsteel and Steel Your Heart for compounding Heartsteel stack growth.⁵⁶⁷
• Try to get Stackosaurus Rex, Heartsteel Quest and Apex Inventor together; Apex Inventor works with Heartsteel and Unending Despair.⁸

• Stackosaurus Rex can be offered after taking Phenomenal Evil; this happened on Malzahar, Mel and Veigar.⁹¹⁰¹¹
• Veigar with level 2 Phenomenal Evil and Stackosaurus Rex gained about 5.25 AP per spell hit.¹²
• Stackosaurus Rex increases Heartsteel stacks alongside Steel Your Heart, with compounding growth; whether those were the only effects needed is uncertain.⁵⁶⁷
• Buying Heartsteel did not grant extra stacks with Stackosaurus Rex because Heartsteel has its own quest.¹³
• Stackosaurus Rex works with the stacks in Tank Engine.¹⁴
• Stackosaurus Rex applies to permanent item stacks, including Heartsteel and Hubris.¹⁵
• Stackosaurus Rex can be offered after taking Phenomenal Evil on Bard, though it is uncertain whether it works with Bard’s passive.¹⁶¹⁷

• With Malphite, taking Phenomenal Evil followed by Stackosaurus Rex gave only one stack from Q, and Stackosaurus Rex appeared to have no effect.¹⁸
• On Smolder, Stackosaurus Rex felt as if it had no effect; whether it was bugged was uncertain.¹⁹
• Stackosaurus Rex did not work with Bard’s passive.¹⁷

• Stackosaurus Rex applied to item stacks after a change whose exact patch was uncertain.²⁰¹⁵
• Stackosaurus Rex only boosted skill stacks, not augments or items.²¹
• Stackosaurus Rex still worked with Steel Your Heart on the newest patch.⁶

Earlier formats

• Since patch 14.15, Stackosaurus Rex no longer grants bonus stacks to everyone in the lobby or stacks with additional copies of itself.²³ 8x2 duos
• Stackosaurus Rex worked with Shyvana’s passive.²⁴ 8x2 duos