Warning: Pre-Alpha

This game is currently in pre-alpha, and at this time, I do not recommend running a game in it yet. Every single game mechanic and piece of lore is subject to potentially breaking changes.

Thank you for your interest in this game! You can follow its development at https://www.youtube.com/@trekiros

-Trek

Encounter Balance

This section will help you build combat scenes of an appropriate difficulty for your players.


Important: When should you balance an encounter?

You should only bother balancing a combat scene if you forced that combat encounter on your players, without giving them a way to bypass, or manipulate the conditions of the fight ahead of time.

Make sure to empower your players with information about the hurdles in their way, so they can put together a cogent plan to get past those hurdles in whichever way they deem best.


Typically, the types of scenes which you'll want to force on your players are either:


  1. The first scene of a new narrative arc, which you use to do exposition and introduce your players to the choices they'll have to make and the hurdles they'll have to face throughout the rest of the arc.
    This could be a combat scene, or something else entirely. But either way, you probably don't want to give your players a chance to even miss this first scene, as it is the hook that will motivate your players to go through the rest of the story.

  2. The last scene of an arc, which is often a boss fight to give the story an appropriately climactic conclusion.
    The choices your players make throughout the arc might decide which boss they end up fighting, but either way, you probably don't want to rob your players of an epic final challenge to end their story on a high note.

These are just the two most common types of forced combat scenes. There might be other scenes you decide to run at your table that you decide to make non-skippable (a common example is random travel encounters, which this book doesn't recommend using, but are still popular for old school players).

Just remember: this game is most fun if you balance forced encounters, and don't balance skippable encounters.

The Narrative Arc mental model:


Estimating an Encounter's Difficulty

Encounter difficulty estimation is a calculation that takes in four inputs and gives you two outputs:

InputsOutputs
X: the players' EHP at the start of the fightTTK: how many rounds the combat should take
Y: their enemies' EHP at the start of the fightD%: a difficulty rating which indicates roughly how much damage the players are expected to take
A: the players' DPR
B: their enemies' DPR

Effective Hit Points (EHP). To calculate the EHP of one combattant, multiply that combattant's current hit points by their damage threshold

Then, to calculate the EHP of one side, sum up the EHP of each combattant within that side.


Damage per Round (DPR). To calculate the DPR of one combattant, first, take the best attack this combattant has, and calculate the average damage this attack would deal.

If the damage includes any exploding dice, the average value for that die can be approximated to half of the die's size, plus 1. For example, 1d10! has an average of 6.111, but you can get an approximation of (10/2)+1=6 which is close enough.


Then, multiply the average damage by the amount of times the character can do this attack in one turn, assuming they have 5 bonus AP if they're a player character.

For example, if the attack costs 4 AP and the character has 14 AP (19 including the 5 Bonus AP), then they can do this attack 4 times per round. If the attack has an average damage of 11, then that character has a DPR of 4x11=44.


Finally, to calculate the DPR of one side, sum up the DPR of every combattant within that side.

Example

Let's say your players have the following HP and DT values. Then, you can calculate the EHP values in bold:

PlayerHPDTEHP
Alice7856
Bob3515
Charlie51050
Total (X):121

And if they have the following damage and AP values, then you can calculate the DPR values in bold:

PlayerDamageAttacksDPR
Alice12 (2d10!)224
Bob7 (1d4!+4)428
Charlie5 (1d8!)420
Total (A):72

Time to Kill (TTK). To calculate the TTK of one side, apply the following formula:


Rounds for the players to kill their enemies:


Rounds for the enemies to kill the players:



The overall TTK is the minimum between the players' TTK and their enemies' TTK:



Difficulty Percentage. The difficulty percentage is a number between 0 and 1 which tells you roughly how much damage your players are expected to take as a result of this fight. To calculate it, use the following formula:


Interpreting the outputs. Once you have calculated TTK and D%, you can interpret how the combat scene will feel for your players:

TTKInterpretation
2-Very short battle
3-5Good battle length
5-8Good but only for an important boss fight
9+Too long
D%Interpretation
<20%Trivially easy
20-40%A challenging battle
40-60%A challenging boss fight!
60-80%At least one PC will probably die
>80%The PCs will probably all die

Expected Power Progression

Assuming you use the guidelines provided in this book for loot and level ups, you can use the following table as an approximation of how powerful your player characters will be.

LevelAverage EHPAverage DPR
04020
1TODOTODO
2TODOTODO
3TODOTODO
4TODOTODO
5TODOTODO
6TODOTODO
7TODOTODO
8TODOTODO
9TODOTODO
1TODOTODO

Expected Enemy Stats

Enemy level is a rough estimation of how powerful an enemy stat block is. As a rule of thumb, avoid using enemies whose level is twice the players' level, or above, as your players might struggle to beat those enemies' damage thresholds

LevelAverage EHPAverage DPR
0510
11515
23020
34525
46030
5TODOTODO
6TODOTODO
7TODOTODO
8TODOTODO
9TODOTODO
1TODOTODO