Viridian the Exhalted's AI Information:

With Viridian being me!

Here are some general rules that the opponent will more often than not use:

Blockers [Yours]:

If 1 of your blockers has a higher power than any of theres then they will not attack.

The only time they will attack is if the attacker either has slayer or a higher power.

Blockers [Foe]:

They will always block any attack you make, regardless of the power of any other untapped creaures you have in play.

They will either use the highest power blocker they have, or the lowest power blocker capable of destroying the attacker.

Tapping Effects [Foe]:

Your opponent will simply tap the highest power untapped creature they can lay their hand[s] on.

I know it doesn't tap, but effects that return things to your hand will always be used on the highest power creatures.

Shield Trigger tapping your opponent gets will be aimed at the highest power, untapped creature that can attack.

Creature Playing:

I'm assuming this, but the AI seems to play the creature it has in its hand with the highestpower or cost that it can afford.

Green decks have a habit of dropping Steel Smashers turn 2 [2 Mana, beats any other 2 cost in hand due to 3000 power]. The same reason Red decks drop Artisan Picora turn 1, even though it smokes their lone mana.

I'm assuming again, but the decks they have seem to like playing unblockables regardless of mana amount.

Creatures that require the destruction of 1 of their own always have the lowest power, lowest cost creature sacrificed to them. The AI is not stupid, so it won't play Black Feather turn 1, thus killing it.