We all understand green numbers, even if they're numbers
Healing is the easiest kind of death prevention to understand. Healing can only stop so much damage -- even if a hero heals his entire life bar every three seconds, if he's hit for a massive damage spike in those three seconds, the only healing that will work is the kind that revives dead party members. Healing is worst against very high damage spike, great against sustained damage, and amazing when combined with anything that divides the amount of incoming damage a hero takes (such as dodge or resistance).
Healing also pairs well with blocking. You can activate heals such as Conviction or Bountiful Chi Resurgence then block to minimize your lost health while your powers recharge. It can't be said enough. Healing is best with other forms of damage reduction; blocking just happens to be available to all characters and stops a lot of damage.
Most of the heals in the game scale to PRE, except for Bionic Shielding (this is getting changed soon), Resurgence, BCR's Resurgent Reiki advantage (which scales to DEX), and Enrage's Endorphin Rush advantage (which scales to CON). If you're planning on using self-heals, some PRE is a good idea.
Mysterious, confusing, and the name of the company who makes the game
"Cryptic numbers" is a term that actually originated in the days of City of Heroes, and it referred to that game's recharge reduction mechanics. Cryptic numbers made a valiant return in CO and govern all forms of CO's multiplicative damage resistance. The term "multiplicative damage resistance" is probably confusing enough, but add in "Cryptic math" to the equation and, well, it ends up looking something like:
incoming damage / 1 + resistance
What does that mean? Well, mathematically, it adds a "share" of the damage equal to the resistance percentage, which is then reduced from the incoming damage. The damage you take is equal to a 100% share, so if you add 200% resistance (say, if you start blocking), you take 1/3 damage.
That's probably as clear as mud, but the net result is that more resistance is good, it just tends to be less effective as you get more of it. This is why I generally don't like ranking up block powers, even on tanks -- block powers give a lot of resistance, which gets diminishing returns.
There are several different types of resistance. The first and most common is Defense. While most powers refer to this as "resistance to damage," many powers reduce damage. Defense is characterized by being additive with the defense gained from equipment. Most powers that grant resistance grant it in the form of defense, including Defiance, Aura of Radiant Protection, and the percentage resistance portion of Invulnerability. Other defense includes bonus typed resistance of all kinds, including the resistance from offensive passives or from defense items that improve a particular type of damage, such as +50% crushing damage resist.
Because there are a lot of powers that grant defense, bonus defense is best for characters that have little of it. Defiance users don't benefit a lot from Aura of Radiant Protection or from bonus elemental resistance items, while dodge heroes benefit a lot.
The second form of resistance is blocking. Every hero has a default block worth a massive 200%, and block powers can upgrade it to 250% or more. Even the default blocking is worth far more than all but the most over-stacked defense, so blocking can make a huge difference in whether or not a hero survives.
Blocking is multiplicative with other resistance, so Defiance users get the same benefit from blocking as everyone else. In fact, because Defiance builds defense over time, a Defiance hero should start a fight blocking so that she gains extra Defiance stacks while staying well-protected.
Naturally, you can't block while attacking, but the third type of resistance works while attacking: pseudo-blocking, which I term "special resistance." Special resistance is multiplicative with other types of resistance, but because it is generally generated by certain block powers when not blocking, there's only one instance of special resistance that can benefit from blocking as well.
The most infamous source of special resistance is Energy Shield's advantage, Laser Knight. The others are all advantages for block powers: Force Sheathe, Telekinetic Reinforcement, and Voracious Darkness, from the Force, Telekinesis, and Darkness shields respectively. Special resistance is very useful, especially Laser Knight, which fires whenever your hero makes a melee attack and reduces damage by a huge amount. Because special resistance multiplies on defense or other damage reduction, it's great for any hero.
Why didn't you dodge!
Dodge mechanics function differently in CO
than in other games because all dodged attacks reduce damage by a hero's Avoidance stat, rather than miss entirely. Additional dodge rating follows a diminishing returns formula, which makes dodge bonuses best with offensive dodge passives like Quarry and Way of the Warrior. Dodge bonuses -- such as those from various Archery powers -- tend to be mostly useless when coupled with Lightning Reflexes because LR tends to hit the dodge soft cap.
Dodge is most effective against slow-activating powers and powers with charge times; a player's dodge percentage is multiplied by the speed of the incoming attack, including its charge time. An attack that takes two or three seconds will always be dodged by a LR hero, while rapid .5 second maintains chop a dodging hero's chance to dodge in half.
Avoidance is unlike every other form of resistance in that it reduces damage by a linear percentage; 50% avoidance means 50% less damage, while 80% avoidance means only 20% incoming damage. This means that while dodge is less reliable than other forms of protection, avoidance is amazing for staying alive. Dodge is great in PvE when coupled with heals or other forms of protection, but dodge is pretty awful on its own. Because Quarry comes with its own heal advantage, it's pretty useful right out of the box.
The blue bubbles, IDF, and the weird stuff
There are three types of linear damage reduction. All of them work similarly; they reduce damage by a fixed amount. One hundred points of reduction amount to 100 less damage.
The first I call "invul reduction" or "minus damage" and is the best. It's possessed by Invulnerability, Unstoppable, and Inertial Dampening Field. Invul reduction is unique because it is applied after all other forms of protection, making it the most useful. This also makes IDF immensely good, since it applies after defense, blocking, and dodging. Also, unlike the other linear damage reduction, invul reduction is never worn down; it doesn't have a finite HP pool.
The second is generally called "click shields" since the main source of it is from click shields like Protection Field and Mindful Reinforcement. It also is granted by the Dual Blades power, Eye of the Storm, and the Unbreakable active defense. These shields are very short-lived, since no forms of protection work before they do. Eye of the Storm and Unbreakable refresh quickly, so they are pretty useful even though defense doesn't work with them.
The final form of linear damage reduction is only granted by Personal Force Field. It's unique in that it applies after defense and blocking but before IDF. Because it's a passive, it's hard to get defense up very high while using PFF, but blocking helps PFF regenerate.
Putting everything together
Get all of that? Here's the main rule of thumb, along with defensive synergy tips:
Defense is the main form of damage reduction, but lots of it has diminishing returns. It works best when coupled with other forms of defense such as dodge, but Defiance is just good, period.
Invul reduction is very good with very high protection values from other things. When coupled with a strong block and self-heals, an Invul tank is nigh-unkillable, and an Unstop brawler has tremendous comeback potential. IDF, which can be granted to any character, is kind of crazy.
Evasion is fluky and other methods of protection are needed to make it work. However, when coupled with those other methods, evasion becomes amazingly strong.
Healing on its own is only so-so but can work in normal solo PvE. It works great as a supplement to other defense, since healing is so common. Regen tanks are among the worst legitimate tanks in the game.
Click shields are best for protecting squishy teammates who have limited defense. They aren't boosted by any other protection, so they tend to get blown through if they are used on tanks. They won't work as a long-term solution, so other methods (like killing the attackers) will be needed to save a target under heavy fire.
PFF is very strange since it has poor synergy with the other Force bubble powers (IDF and PF). It works best with a good block power or perhaps a special resistance block such as Energy Shield. I could probably write a whole column on this passive.
No matter what kind of hero you are, Archetype or Freeform, tank, support, DPS, or hybrid, knowing how the game's defense mechanics work is critically important, especially if you're using Dodge. Picking a few powers at random might work OK, but knowing how powers work lets you explore more powers than Bite and Regeneration and really get creative with your builds.
When he's not touring the streets of Millennium City or rolling mooks in Vibora Bay, Patrick Mackey goes Behind the Mask to bring you the nitty-gritty of the superhero world every Thursday. Whether it's expert analysis of Champions Online's game mechanics or his chronicled hatred of roleplaying vampires, Patrick holds nothing back.