The developers of Diablo IV give more details on the game's systems, including the permanent transformation of certain map elements, strongholds, and how they handled damage mitigation for players, but also demons.

Lead World Designer Art Peshkov, Lead Systems Designer Meng Song, and Game Director Joe Shely discussed more technical and specific elements than usual during the February 28 livestream. Diablo 4's release date is just a few months away, and the open beta will allow many players to experience firsthand what the game has to offer.

Armor, resistances and damage mitigation

We'll start with a technical section, which will probably appeal more to fans of theorycraft and optimization in general. Indeed, the way damage mitigation is applied to players and monsters greatly alters the balancing of the game. And by extension, it affects how high level builds will look.

Armor

Armor item slots are always used to reduce damage. Each item has an Item Power level, based on the power of the monster that dropped it. So the more powerful and high-level monsters you kill, the better the Diablo IV items will be on average, although this does not guarantee that they will necessarily have the most interesting stats for your character.

The amount of armor on items is related to Item Power, which is one reason why they are often better.

Armor reduces the physical damage inflicted by monsters. The minimum is 5%, and the maximum is 85%. But the developers consider that players will start the game around 10%, and end up around 45% at high levels. Expect it to go higher with specialized builds and high-level content.

Elemental Resistances

Enemies also inflict elemental damage, which can lead to extreme situations, depending on the player's resistance to that damage. A boss could be trivial for one player, and impossible to kill for another, since it would be one shot by an attack. So, basically, the armor also offers a percentage of elemental damage reduction, equal to half the physical damage reduction.

However, elemental resistances should not be neglected, since penalties will be applied to players when they increase the difficulty of the game. There is a -20% elemental damage resistance penalty when increasing the World Tier to 2 and 3. This penalty increases to -30% for Tier 4. A similar mechanism was already present in Diablo 2.

Elemental resistances can be obtained through talents and other sources afterwards. Some common examples are Diablo 4 item affixes, paragon bonuses, etc.

Balancing

The developers use different graphs, with numbers, to balance the difficulty. Monsters hurt less at the beginning of the game, when players have little armor.

Enemies' damage and armor penetration increase with their level. On the other hand, the amount of damage reduction per point of armor decreases with each level.

This means that you have to search for new equipment and increase your armor constantly in order to survive.

However, these are not the only options, as damage reduction is introduced afterwards with talents, legendary bonuses, etc.

Of course, higher level monsters have to take more damage. Historically, monsters did not have armor. But in order for them to be a challenge for high level players, they had to be given trillions of hit points, which required the player to deal billions of damage to them. Diablo 3 is infamous for number inflation, as it's completely unreadable on screen, as well as being quite ridiculous. So instead, monsters will gain damage reductions with levels.

This has introduced another problem though, with players taking less damage after leveling up, since monsters' levels are often based on this (this might bring back bad memories for WoW players). An adjustment has been made so that monster damage reductions are a bit lower than player natural damage gains.

Bastions

The team has returned to one of the new features of Diablo 4, closely related to the permanent open world. Each of the game's five regions includes a number of bastions, important and unique places infested with evil. They often contain unique bosses and rewards. These are instanced areas for each player, as completing a stronghold will permanently alter a section of the map for that character.

Clearing them by force of arms can unlock different types of content: it can be a camp with merchants, a waypoint, a shortcut on the map, a dungeon entrance, or a new side quest.

It will also offer quite a bit of renown for the corresponding region, which allows you to unlock permanent bonuses for all your characters in that realm.

Bastions have a minimum level, so attacking them too early can lead to a quick death.