[engine limitation]Protection protects from trample damage

[Acra]

Like in the title. I think it should be like: deal "lethal" damage, protection prevents damage to creature, rest goes to player

[BAgate]

Actually this is correct. The relevant rule is "702.16e Any damage that would be dealt by sources that have the stated quality to a permanent or player with protection is prevented." So if a creature with protection from something blocks that something it suffers 0 damage and there is none left over to trample.

[Korath]

No, Acra has it right.

702.19b The controller of an attacking creature with trample first assigns damage to the creature(s) blocking it. Once all those blocking creatures are assigned lethal damage, any remaining damage is assigned as its controller chooses among those blocking creatures and the player or planeswalker the creature is attacking. When checking for assigned lethal damage, take into account damage already marked on the creature and damage from other creatures that's being assigned during the same combat damage step, but not any abilities or effects that might change the amount of damage that's actually dealt. The attacking creature's controller need not assign lethal damage to all those blocking creatures but in that case can't assign any damage to the player or planeswalker it's attacking.
Example: A 2/2 creature that can block an additional creature blocks two attackers: a 1/1 with no abilities and a 3/3 with trample. The active player could assign 1 damage from the first attacker and 1 damage from the second to the blocking creature, and 2 damage to the defending player from the creature with trample.
Example: A 6/6 green creature with trample is blocked by a 2/2 creature with protection from green. The attacking creature's controller must assign at least 2 damage to the blocker, even though that damage will be prevented by the blocker's protection ability. The attacking creature's controller can divide the rest of the damage as he or she chooses between the blocking creature and the defending player.

The second example deals with this situation specifically.

Manalink doesn't handle tramplers blocked by multiple creatures correctly, either: it doesn't force all of them to be dealt lethal damage before assigning damage to the player. Plus, it won't let you assign more than lethal damage to a singular blocking creature.

(And just to complicate things further, a trampler with deathtouch only needs to assign one point of damage to each blocking creature for it to be lethal.)

On the other hand, I'd just as soon it not be fixed until we can make the AI account for the modern rules in its blocking choices, so it's on an even footing. That's not likely to be anytime soon.

[BAgate]

That will teach me to read the whole section. Someday I need to read all the modern rules just to see how outdated some of my memories are.

But what are the problems with the AI and blocking? If I recall it actually blocks as if the trample rules are enforced.

[Aswan jaguar]

Not trample but generally AI blocking issues
-AI doesn't get deathtouch so it won't use only the deathtouch creature to block and kill an attacker but will use as many blockers to make combat damage equal to creatures power as a result player can kill a lot more defenders.
-Same for Indestructibility but worse as it has no chance to kill that attacker.
-Same but worse AI blocking decisions as AI doesn't get poison-infect and will let attacker unblockable if AI has enough life AI considers is safe from it.
-Same with Commander damage in EDH games.
and more,

Attacking-Trample
-For both AI and player when attacking you can assign all damage of creature with trample to a single blocker although you are blocked by more defenders and under modern rules you have to assign first lethal damage to all defenders and then trample the damage to player (I enforce that rule to me)but AI will choose of course to assign lethal damage to one blocker (if AI can win this way that turn) with toughness enough to trample the damage for the win.

[BAgate]

I knew most of that, I was really referring to the fact that the AI tends to block creatures with trample in a reasonably intelligent way as if the modern rules apply (i.e. with enough total toughness to prevent damage getting through). Although why the AI doesn't understand poison I've never understood, it was part of the original game.

And for the record, if we're talking AI improvements, fixing the when to attack issues should come before any blocking issues get addressed.