What this ruleset does to the battle is to grant all the cards present in the battle the Scattershot ability, which in case you don't know, what it does is to cause the attacks of that card to be completely random.

The first condition you should know about this ruleset is that although the ability is granted to all cards on the field of battle, only Ranged and Magic attack cards will actually use it, and that is because Melee attack cards cannot activate this ability don't matter what. So from the beginning of the battle we already know that specific attack abilities such as Sneak, Snipe or Opportunity are nullified as long as the monsters that have those abilities are not Melee attack. Another thing to keep in mind with this ruleset is that the Taunt ability becomes totally useless when Aimless is present.

How do you take advantage of this ruleset?

From my point of view and my way of play the battles there are two ways to play this ruleset when it appears, in the first one you will take advantage of its effect of the Scattershot to align powerful Magic Attack or Ranged cards to do a lot of damage each turn, and if possible add abilities that are beneficial to this strategy, like Blast or any other that applies debuff to the enemy when you hit him, like Poison. I recommend this for high mana battles.

The second way that I recommend is to ignore the ruleset completely by playing only melee damage based lineups with powerfull attack and protect yourself with armor abilities, Opportunity will be lethal here because most magic and ranged attack cards are low life, I recommend this more for low mana battles.