Actually, you should answer two questions here. What do you need more: preventing damage or preventing the other effects of the enemy cards? And would a random card from your deck be better than the enemy attack? Both answers depend on your deck and the situation. A dwarven control wizard (especially a member of 3 wizards team) may prefer Toughness, especially versus enemy warriors, since he needs to survive just one attack - you're going to teleport the enemy away after it. The mage would definitely prefer a card from his own deck since Winds Of War or Whirlwind Enemies are the best cards he can get. A dwarven warrior should prefer Duck, though, since he has a lot of hit points and can survive one attack, but will lose if he gets encumbered or teleported. He may have a lot of great cards in his deck, but most of these cards would be unusable if he would be unable to get close to the enemy. I'd prefer Duck for my warrior even at close range, since every attack counts, and the enemy may simply lack the weak attacks! But even if the enemy has them, he still loses the tempo trying to trigger my Duck. He's hitting me with a weak attack - I hit him with a strong one If my warrior has Mass Frenzy (and he usually does), even the weak attack wouldn't be weak in response. Plus, Duck is invaluable when the enemy tries to bash you away from the victory area or activate All-Out Attack. Would he play a weak attack to waste All-Out Attack, or risk wasting a strong attack to my Duck? Toughness is inferior here, since I need only attacks, and they cannot fill more than 30-40% of my deck, and some of them are going to be weak too.
That is a good point, Ector. I agree that duck works best on a warrior compared to wizard or cleric. He is going to be hit with more attacks and effects than his comrades, and ducking a Frost Jolt is great. However, what Toughness still has going for it is that it doesn't fail. It's more consistent. I'll explain more with my actual experience with it: Okay, so for a week or so I ran a dwarf warrior/warrior/cleric build with 6 ducks (2 on each guy). With the indispensable Slippery Shield, I had 5 blocks on each dude. Running a lesser shield was still going to leave me with 5 blocks, so I thought I might as well include those Hard To Pin Downs to give me the option to play the block if it wasn't going to get triggered. But even with the option to just play Hard To Pin Down (which gets rid of it's card advantage), I still had so many blocks, I often had trouble holding on to all of my blocks and attacks. When a dwarf warrior has 1 or 2 blocks revealed, the opponent tends to just focus on other characters. Sometimes this is good, but more often than not you wind up discarding or playing blocks to keep attacks, or vice versa. And that's bad for consistency. Toughness just triggers and replaces itself. You usually don't have to deal with it clogging up your hand at turn end. The consistency is why so many players think it's overpowered. I agree that duck might be a better choice than toughness in the right build, but given the breadth of options the dwarf warrior has, I'd usually go with something else. (Dwarf Warrior rocks with Advanced Ferocity/Perfect Ferocity, or Apprentice Ferocity/Raging Battler, heck even Solid Rock)
Ector your response illuminates that some answers are situationally true or false or provide better options. However, again, for higher ratings toughness is more consistent, can completely mitigate an attack, and is more successful for deck planning and developing tactics/strategies for opponents. Duck inserts too many random variables into the mix to make it reliable, consistent, and capable of planning around. On a side note, that's also a reason people at higher ratings don't use aoa very often either.
All I can say: I will try Perfect Stoutness as soon as I get it If you see that your opponent refuses to attack your warrior just because of the revealed Hard to Pin Down, use it for movement. Well, at least the only item with two Toughness (Perfect Toughness) has bad third card, while the item with two Ducks (Perfect Stoutness) have good one
Officer's Harness isn't that much better than Rusty Armor. At least you can keep it if you draw it early in the game.
That's why it IS much better. It's almost like a positive trait that isn't very helpful, but lasts forever and cannot be removed by Purge or attaching a lot of negative cards to you. It can be removed by Perplexing Rays, but, honestly, that's the best part of the Harness: it reduces the probability of losing the most valuable cards to perplexion.