# Measuring Power

oltyan
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Joined: 04/25/2012

Hello all,

I've been mathcrafting the balance to my game prior to having people play it, so I can have a basis for future tweaking. I've done this by assigning numeric point values to abilities in my game. To break it down, each card has

• Abilities - 3-8 points (3 for basic, +2 for strong effect or negative for enemy, +3 another for major effect)
• Safe + 2 or Risky + 0 (does it require a roll to succeed or is automatic)
• Exhausting + 3 or Suicidal + 0 (do you tap or sacrifice to activate)
• Modifier +X

The Abilities can appear on different cards, but some cards are able to play them as a tap vs a sacrifice (thus a major factor in my mind, and through playtesting)

The modifier influences the end result. A safe ability could provide a +1 to something, but it could also provide a +3 on a different card. Additionally, a Risky action could have a + modified to make it slightly less risky.

All abilities are rolled on 1d6. Target difficulty is generally 4.

I don't expect to nail 100% accuracy on the first pass, but I use this sort of setup to create a relative balance. I modeled it after the lessons I learned from conducting Planning Poker, using Story Points as a relative measure of difficulty. Essentially, I may not know if ability 1 is more powerful than ability 2 in absolutes, but in a general scale, I feel comfortable rating it higher or lower than another ability (through some playtesting of the abilities). Also, this is how the TCG designers I worked with did their first pass on balance.

I was wondering if anyone else had different approaches, and how you balanced over time. For me, its important to have metrics and benchmarks, and after a session have the ability to compare my numbers and relative rankings with what the players felt.

This is a sample of a sheet I'm using. The "rarity" I use as a guide for the number of points a Crew Card should have. I try to have, for every 6 cards, 3 Common, 2 Uncommon, and 1 Rare level of power.

So how do you balance your games?

• kos
Offline
Joined: 01/17/2011

My standard approach to balancing units/cards/etc that have attributes or abilities is to use a spreadsheet with two sheets.
- The first sheet contains a list of cards with each of their abilities in the cells to the right. Further to the right are a set of columns with lookups to the cost of each ability. On the leftmost column is the card value (which is calculated as the sum of all the abilities).
- The second sheet contains a list of all abilities along with the points cost of each.

I generally start with a nominal cost for all abilities (i.e. cost = 1), then go through the list making off-the-top-of-my-head decisions about which ones I think are more powerful than others given the ruleset (i.e. cost = 2 or 3).

After some playtesting, I come back and revise the list of special abilities as needed. The nice thing is that via the lookups the changes to the ability costs get propogated through all the cards, rather than doing it manually.

I found early on that it is important to keep the versions of my rules and the spreadsheet matching, since sometimes even simple changes to the rules can have drastic effects on the relative cost of various abilities.

I usually go through multiple different ways of calculating the card costs, too, before I settle down on a method that I'm happy with. This is also affected by the ruleset, and often there is a circular feedback mechanism.

Take for example a game where a unit can use all of its special abilities each round. In this case I would probably start with a simple "sum all of the abilities" formula to calculate the cost of the card. Let's say that after some design changes each unit can only use one ability per turn. Now the units with multiple abilities are overpriced, because the rules change means that multiple abilities provide extra flexibility but not necessarily extra power. So I might change my formula to "the most expensive ability plus half the sum of all the other abilities." I haven't changed the cost of any of the abilities, but by changing my formula I've significantly altered the cost of the cards.

Take another example where I have two abilities: Stealth and Berzerk. Initially I had in mind that they would be equivalently powerful, just used in different ways to achieve victory. After playtesting I find that Berzerk is way more powerful than Stealth. I could just increase the cost of Berzerk to match its effectiveness, or I could change the rules to nerf Berzerk or buff Stealth while leaving their costs the same. The way I choose to balance it depends on how I intend the game to be played.

Regards,
kos