Discussion about the game's artificial intelligence.

In many ways.
Firstly, the AI constantly uses some kind of stupid tactic of applying "dodge." Enemy heroes, when they have this ability, often do nothing but stack dodge on everyone, even if you don't have any ranged units. When Sinistar, in a duel with a lucky Sorcerer, started applying dodge to everyone instead of using cool spells, I just wanted to facepalm.
Secondly, continuing with the dodge tactic, all enemy ranged units and ballistas start targeting units with dodge. If you place two units next to each other and one applies dodge, all enemy ranged units immediately target the unit with dodge, which is completely absurd.
Furthermore, the AI practically never tries to block your ranged units. In previous versions, they always tried to block ranged units when possible, but now they just beat up melee units and don't even try to block ranged units.
Also, the AI has become worse at using racial abilities, such as opening portals and using runes. It was reluctant to use portals before, but it could still do it, especially if a stack had no attack, but now it completely ignores them. It also often ignores runes.
If you block stacks with a crystal and a wall, it just gets stuck; I don't remember how it was in 3.0, but it seemed like it would at least sometimes try to break through.
In short, the AI in 3.1 is not just dumber than in all previous patches and versions of the fifth game, but significantly dumber.
In the same Lords of the North, the AI could sometimes surprise you.