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Istarian Combat Overhaul - Old
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Istarian Combat Overhaul

Wait, what?  Yes, you read that correctly, starting in 2022 we’re revisiting the combat system in Istaria and giving some key portions significant upgrades and/or rewrites.

The combat revamp is now in pre-alpha on Blight! This revisit of Istaria's combat systems intends to improve combat, assist in balancing, and offer new features. We will be listening carefully to player feedback during this extended testing period. We expect there to be significant changes, based on your feedback. Stay up to date with us on Discord, forums, and support.

You can send in feedback through:

        Support system:




Please note that the support site and email guarantee your feedback is seen by every developer. Discord posts may be missed by some on the team, but you do get more back and forth communication with Discord.

What is the point of this overhaul?

There are three main goals for overhauling the combat system in Istaria: Chronicles of the Gifted.  These changes will expand our ability to offer creative rewards and unique build opportunities without feeling forced into a single setup.

To expand upon the reasons above, combat can be very complicated from both the player’s and the developer’s perspectives.  How a skill impacts portions of the combat code can be challenging to determine, contributions are often unclear, and the results are often murky or inconclusive.

Consider the dodge skill and check. The current combat code performs three to-hit checks in a row; a regular to-hit, a check to determine if dodge should be checked, and then a third check to calculate if the attack was actually dodged.  To make matters even more complicated, to-hit checks of all types were based upon a “contest of skills” between the player and the target. This may have seemed fine on paper, but does not work well in practice.  Because the player cannot see or predict the combat skill of their targets there is no way to truly get an idea of what their chance to-hit or dodge might be against any particular enemy.

The reverse also held true for to-hit and dodge.  Since the enemy’s attack skill could not be seen, the player’s chances to avoid an attack could not be easily calculated or displayed.  Adding wards, or damage-type specific avoidance, into the mix simply made matters even worse.

Contrast that with many other MMOs where calculations are more often based upon the player’s skill and the target’s adventure rating.  Both values are well known and visible to players and therefore the results can be easily understood and frequently displayed for the players to see.

Other systems within Istaria were similarly complicated and difficult to explain and understand, such as damage mitigation and resistances.  It is the primary goal of this overhaul to streamline these types of processes and to create a more well-rounded system where everyone (player and developer) can clearly understand the inputs and outputs of the combat calculations.  Changes of this sort help create more predictability and, as a result, more ease by which developers can balance content that is added to the game, and for players to strategize their attacks.

To better illustrate some of the changes, here’s a flowchart illustrating Istaria’s original combat flow for determining hits and avoidance:

Now, here’s a flowchart illustrating the revamped combat for determining hits and avoidance.

Both systems are complex, but the second (newer) system performs fewer checks for each avoidance or hit type and it is this part that helps create more predictability and visibility.  Each piece of the combat system was approached in this manner, to decide if it was useful, if it was predictable, if it could be easily displayed to the player, and, if not, how it could be made that way.

Some systems were almost entirely unused, such as Wards and Attack Skill (called Penetration in some cases), while other systems were confusing and highly underused, such as Ethereal Armor and Resistances.  The new changes allowed us to find ways to integrate some of these, previously under-utilized systems, to make them more useful and to give players more control over their impact.  

The changes also allowed us to find places where we could easily introduce new features, such as Glancing Hits, Critical Hits, Critical Heals and Tactical Mastery.  All of these features, when combined, produce a system that we feel is greatly improved over the old system, should prove to be more fun for players and easier for the team here at Virtrium to create and balance new content.

Before we get to the details of the changes, we want everyone to know that we understand that change itself can be frightening. It is for this reason that we have written this document in an attempt to be transparent about our attempts to improve the game and to invite discussion as well as, we hope, generate excitement regarding the forthcoming changes.

Important Terms and Definitions

What specifically has been changed?

Hit Table

The old system performed a series of random number checks in sequence to determine if the attack hit, or dodged, or parried, and so on.  This approach created even more unpredictability and so it was replaced with a system called a hit table (or an attack table as it is sometimes called).

What is a hit table?

Essentially it is a table of potential results of an attack that includes miss, dodge, block, parry, hit, critical hit, and even glancing hit. All results are built into this table and then checked in a specific order to determine the result of the attack. The benefit of this approach is that a single random number is used for all checks creating more predictability.

How is this different from the previous system?

The simplest answer is that it reduces the number of random number rolls that are required, making the results far more predictable.  Here is a quick breakdown of the old system. Notice how there are seven random number rolls marked on the chart? Each time you perform another roll, you introduce more unpredictability and you further reduce the predictability of each check.

An example with numbers can help illustrate it even better for some.  If you have a 75% chance to hit, a 15% chance to dodge, 15% to block and 15% to parry.  Your actual percentages to dodge, block and parry are reduced because of the checks that are done before. Your dodge is reduced to 11.25%, your block to 9.98%, and your parry to 8.99%.

Why is a hit table better?

For two big reasons. First, the number of random number rolls is reduced by seven to one. That helps introduce a lot of predictability right off the bat! Second, because the percentage chance is included in the table it is not impacted by other percentages in the table.

To illustrate the difference, here is a quick chart:

What is the order of checks in the hit table?

While the order does not impact the percentage chance for any of the potential results, it can be important for players to be able to determine what they wish to prioritize on their gear or training points.  Therefore, the table order is as follows:


Previously the to-hit code in Istaria was extremely complicated; it used both the attacker’s weapon skill, the defender’s evasion skill, as well as the attacker’s and defender’s dexterity values.  These values were given weights and a calculation was performed to determine if the result of the attack was a hit or miss.  As mentioned at the start of this document, this created a situation where the outcome was not known to the player as they would have no knowledge of the target’s skills or stats.

The replacement we have written simplifies this situation by basing the large majority of the to-hit calculation upon a difference in rating between the attacker and target.  Unlike the prior calculations this formula creates predictable results that a player can calculate against any enemy in the game using two simple values; Attacker Rating and Defender Rating.

Player Adventure-Rating 100 or Higher

When the Player Adventure Rating (as the attacker) is greater than or equal to 100 and the Defender Rating is greater than the player’s rating, the to-hit chance (before offensive bonus is added) is capped at 75%.  This was done for three reasons:

  1. To account for the difference in rating when involving the rating cap on individual schools or monsters that can exceed rating 120.  By standardizing this situation, differences between Dragons and Bipeds when fighting monsters above rating 120 can be properly addressed.
  2. To account for situations where a player has a high rating, but has switched to a school that has a low level.
  3. To account for situations where a player with a high rating (100 or greater) is fighting a monster with a lower rating (below 100).
Offensive Bonus

Most to-hit numbers using the base formulas will be in the 60 to 90% range, so you might be wondering how you can make up the difference?  Well, that is where the attacker’s offensive skill and dexterity (or focus for magical attacks) comes into play.  This value is a bonus that is calculated using the attacker’s offensive skill (e.g. 1-hand slash, flame, dragon breath, etc) and stat and applied to a curve with diminishing returns.  The resulting percentage is then added to the to-hit target number.

What does this mean?  It means that your offensive skill and dexterity can produce a bonus to your to-hit with a range of 1% to 25%.  Reaching those upper values may prove to be challenging, however, due to diminishing returns.


Like to-hit and other calculations, the goal of overhauling dodge was to create a situation in which the results and the player’s contributions were more predictable.  Gone from the calculation is the second to-hit check and, instead, the defender’s evasion skill and dodge stat are combined and then applied to a diminishing returns curve (can produce a value between 1 and 12%) that is then added to a base % chance to dodge that all players (and monsters) will have.

In addition, we have taken wards into account for dodging.  Previously wards were added to the evasion skill of the calculation, but since many of the values involved in the checks were not known by players, it was extremely difficult to see any impact upon the combat results.  Under the new system, wards add as much value to the dodge calculation as the Dodge skill itself.

The new system scales a defender’s ward value versus a specific damage type onto a diminishing returns curve producing a result between 1 and 12% and this value is then added directly to the previous dodge calculation.

One additional calculation to the dodge chance is that the difference between the Defender’s and Attacker’s rating will be taken into account and can adjust the dodge chance up or down.

Finally, dodge has been altered to no longer be blocked behind a passive ability. Instead, dodging is available and checked for all players and monsters.


Block works in a manner very similar to dodge.  Removed is the second to-hit check, replaced instead with a simple calculation involving the defender’s shield skill, strength, and any block bonuses.  These values are added together and applied to a diminishing returns curve that produces a value between 1 and 10%.  A base blocking value that all players (and monsters) have is added to the calculated result, giving the final block %.  

One additional calculation to the block chance is that the difference between the Defender’s and Attacker’s rating will be taken into account and can adjust the block chance up or down.

As before, blocking continues to require a shield or specific buff to enable the capability.


Parry is almost an exact copy of Block using the defender’s weapon skill, dexterity, and any parry bonuses applied to a diminishing returns curve that produces a value between 1 and 10%.  

One additional calculation to the parry chance is that the difference between the Defender’s and Attacker’s rating will be taken into account and can adjust the parry chance up or down.

As before, parrying continues to require a weapon or specific buff to enable the capability.

Damage Mitigation

The most complex part of the overhaul, damage mitigation refers to the process by which armor and resistances reduce the damage that a defender would take from a hit.  Previously, Istaria used a system by which armor directly reduced damage by ratio (armor / 45 delay-adjusted).  This meant that your armor’s impact varied based upon the delay of the attack which, as another unknown value, made it extremely hard to calculate and also made the effectiveness of your armor fluctuate against each enemy you fought.

The new system produces a percentage of mitigation against attacks that is more dependent upon the rating of attacker and defender but also contains some changes that may need more explanation.  Some of the key changes are:

Mitigation %

The largest change (mentioned above) replaces the system by which armor reduces individual damage via a delay-adjusted amount and instead creates a percentage by which damage is directly reduced.

Armor’s impact against damage is applied to a curve with diminishing returns that takes the attacker’s rating into account and produces a percentage of reduction.  The goal of this change is to reward players for wearing some armor, but to make it challenging to achieve the highest levels of mitigation.

The mitigation percentage is applied directly to the amount of damage done in all three hit cases (glance, hit and critical hit).

Special cases exist when the defender is a player and is rating 100 or higher and fighting Epic monsters (rating 150 or above) or Elite monsters (rating 130 or above).  Against these types of monsters the calculated mitigation % is further reduced by a flat rate.

Against any type of enemy, the maximum mitigation% that armor can provide against an attack is capped at 75%.  The goal of this cap is to allow for a larger role by resistances (explained below).

Armor Effectiveness vs Damage Types

A new concept that changing the concept of damage mitigation allowed us to incorporate was that of armor effectiveness.  What this means is that your armor is less effective at mitigating damage against certain types of damage.  This concept was introduced to make resistances far more effective and useful in combat.  

Effectiveness rate modifies the mitigation % from armor:

What does this mean exactly? It means that the armor value that is used to calculate the mitigation % is less effective against certain damage types.  So, for example, if you had 1000 armor, against:


Under the old system, resistance to a particular damage type was added to the defender’s armor value to be included in damage mitigation.  This created a situation where you needed to have huge amounts of resistance in order to have any meaningful impact upon incoming damage.

Using the new system, resistance to a damage type is applied to a curve with diminishing returns to produce a result between 0 and 25%. This value is then added to the armor mitigation % to generate the final mitigation rate.  This system differs from the old system by making any amount of resistance provide at least a small amount of visible bonus that will be useful in any combat situation.

The final mitigation %, unlike armor’s mitigation%, can be above 75%.

Damage Resistance

Resistance to damage types has changed in the overhaul and it is important to take note of the changes. In the old system, each damage type had a corresponding resistance statistic. This created a large number of resistances, many of which were unused by players.

In the new system, the resistance types have been reduced to four:

Ethereal Armor/Ethereal Damage

With the introduction of armor effectiveness, the need for ethereal armor and ethereal damage are no longer necessary.  This was always a confusing part of the game that caused questions and consternation among players.  Some monsters could inflict damage on the ethereal damage path, but it wasn’t a separate damage type.  Instead, it was a modifier to existing damage types such as flame; ethereal flame vs physical flame.

As a result of this change, the use of ethereal damage/armor has become obsolete and items or spells that utilize it will be updated.  Specifics of these updates will be forthcoming.

Attack and Action Delay

Delay when casting or executing attacks is a core concept of any game.  Many spells have a pre-delay, that is a built-in casting time, while many melee combat abilities have a post-delay, a cooldown after the ability is used.

Delay Mods are commonly used to reduce the amount of build-up and cooldown around the use of these abilities and spells by means of buffs and items.  This overhaul adjusts this system to make direct modification of delay a little more complex and focused on the new Tactical Mastery attribute (see below for more on this attribute).

In the new system, Tactical Mastery is combined with a fractional value taken from Dexterity (or Focus depending upon the type of ability) and applied against a curve with diminishing returns to generate a percentage of delay reduction.  Delay modifiers from buffs and items can still be applied, but they are scaled down and added to the above percentage.  

What does this mean for me?

It means that your contributions to the Tactical Mastery attribute as well as your Dexterity and/or Focus will contribute towards improvements in an ability’s delay without the need to utilize buffs or other sources.  

Are there  limitations?

Yes, no matter what the maximum reduction is 75% and no item’s delay can be reduced below 1 second.

Damage Scaling

Damage scaling has always been a part of the game and represents your Stat and Skill contribution to the damage output.  For player spells and spell-attacks, however, this has been updated to make use of a diminishing returns curve and to remove the delay-adjustment to stat/skill.

What does this mean?  

Previously, standard damage was enhanced by a delay-adjusted calculation that included your offensive attribute (Strength for non-spell attacks, Power for spell attacks) and your offensive skill (e.g. Tooth & Claw, Primal, Flame, Two-handed crush, etc).  

The new system, which applies solely for spell attacks, takes these same values (offensive attribute and offensive skill) and applies them to a curve.  This curve generates a modification percentage (from 0 to 40%) that the base damage is then multiplied by. For this situation, delay is no longer taken into account.

Are there any new features that have been added?

Glancing Hits

One new feature added with this overhaul is the concept of a glancing hit.  A glancing hit is a miss that was very close to a hit (within 10%).  You could consider this to be a sword strike that slid across the target’s armor, or went through their shirt (but missed their body) or cut the hairs on their head.  

The way it works takes a bit of explanation.  For example, if you had a to-hit target of 75 (or below) and you rolled a 77 it would previously be treated as a miss.  Using the new glancing hit code, since your roll was within 10% of the target (7.5%) it would be considered a glancing (or partial) hit.

Partial hits still do some damage, but the percentage of the original damage is determined by how close your to-hit roll was to the original target.  Using the above example, the closer you were to 75% the more damage (up to 50% of the total) your glance would do.  The further from 75% you were (or closer you were to 82.5% in this case), the less damage (down to 10% of the total) you would do.

The benefit to glancing hits isn’t just turning a miss into a partial hit, but it’s the fact that, for purposes of debuffs, glancing hits still count as hits.

Critical Hits

Another new feature we’ve added is the concept of a critical hit.  You’re more than likely familiar with critical hits from other games and it will work in a similar manner in Istaria.  Critical Hits will cause, at present time, 1.5x damage.  

What is your chance to cause a critical hit?

Critical Hits use a new skill called Critical Rating.  This is a skill that can have Training Points assigned along with Techniques and other buffs.  This value is incorporated into a calculation with diminishing returns that, when combined with the defender’s rating, produces a % chance.   The higher your rating, the greater your chance to cause a critical hit on an attack.

What stats contribute to Critical Rating?  

Dexterity and Focus at 5% each.  In addition to a direct impact upon critical rating, the stats also provide a direct bonus to the critical hit % chance on a diminishing returns scale from 1 to 5%.  Which of these stats is utilized depends upon whether or not the attack is magical or not.

It should be noted that only players can get critical hits, monsters cannot. The reasoning behind this decision was two-fold.  First, to give players something special that monsters could not have. Second, as a player you could not see what the monster’s critical hit chance was and so being blind-sided by a 50% increase in damage from a powerful attack like Surtheim’s Combust or Selenia’s Brilliant Rage might upset some players. We thought it best to avoid this.

Tactical Mastery

Tactical Mastery is a new attribute that determines how “hard” an attack hits. This value is applied to a scaling factor to get a percentage that then reduces the DamageMitigation%. This percentage is influenced by Dexterity or Focus depending upon the type of attack (physical or magical), but also by the difference in rating between the attacker and defender.  If you attack monsters that are higher rating than you, your tactical mastery will have less impact.

Tactical Mastery can be boosted by Training Points, techniques or other means and can provide an alternative means by which damage against a target is boosted.  


Player_A does 100 points (before mitigation) against Monster_A.

Monster_A has 25% damage mitigation against attacks

Player_A will therefore do 75 points of damage to Monster_A

Player_A, however, also has a Tactical Mastery % of 15

This value reduces Monster_A’s mitigation from 25% to 10%

Player_A, as a result, does 90 points of damage to Monster_A


Penetration is a value that might show up on buffs or debuffs and can be listed as Armor Penetration, Arcane Penetration or Mystical Penetration.  This is an additional value that can influence how hard an attack hits against specific damage categories.  Penetration is included in the Tactical Mastery formula as below:

This should not be confused with attack-skill or to-hit-bonus as it worked in the old system.  Under the old system, penetration was applied to the to-hit check whereas under the new system it works to reduce the mitigation % of a defender.

Critical Heals

Another new feature is the concept of critical heals, which are similar to critical hits, but for healing and are based upon the caster’s relevant skill and focus attribute.  The combined skill and focus value are scaled on a diminishing returns curve to produce a % chance between 0 and 10.  Like critical hits, critical heals will heal, at present, 1.5 times the normal heal amount.

It should be noted that critical heals only apply to heals that are a flat amount (X to Y) rather than Heals-over-Time or % Heals.  Fortunately for players, critical heals are also only available to players, not monsters. The reasoning behind this decision is similar to the one for critical hits and monsters.


Are Dexterity and Focus obsolete now that they aren’t used in To-Hit?

My armor no longer protects me as well against arcane or mystical attacks?

What about my ethereal armor or abilities that convert damage to ethereal?

Why was tactical mastery introduced?

What about my items, abilities, and other items I have acquired?  Will they change?

What about my training points?

Does this mean I can’t stack Delay Mods any longer?

What is a diminishing returns curve?

What is happening to my existing skills?

My items are useless now, what can I do?

Is unstoppable damage remaining in this system?

Will we be able to see these values in-game?


As with any large change, numbers are subject to change for balancing.  Please keep that in mind as we move forward.