Category Archives: Game Design

Recent Feedback for Monster Zoo

Over the past couple of weekends, I have been playtesting Monster Zoo with a few different groups (and participating in Grant Rodiek’s Prototype PenPal Program). Most players are enjoying the game and I’m pleased with the feedback so far.

Here are some of the findings at this stage:

  • The game is fun: The response has been good from a mix of gamers. The theme is great and a lot of people really like the art. The game is easy to learn and new players can learn how to play in a short amount of time.
  • Minor edits for clarity: While most players felt the rules were easy to understand, there were a few minor tweaks that could have helped clarify a few things. There is some wording that could be modified such as “Swap a Monster from your Zoo with another player’s Zoo”. The edited version will say “Trade a Monster from your Zoo with a Monster from another player’s Zoo.” The previous version could be interpreted to mean that you only need to swap one Monster from your zoo to take ALL the Monsters in another player’s Zoo.
  • Reduce food costs: There are too many of the top end cards with high food costs. I need to tweak the food cost distribution down slightly to speed the game up.
  • More combos: While there are some interesting combos in the game, players were eager for more.

Based on this feedback and earlier comments, I have made the following changes to the game:

  • Increased the game speed: Instead of starting the game with 3 Zookee Zoogly / 7 Dirty Socks cards, players will now start with 4 Zookee Zoogly / 6 Dirty Socks cards. This has the effect of increasing the chances that players will be able to move cards into their Zoo, speeding up the rate of point gains throughout the game.
  • Tweaked the Food cost distribution down: I reduced the food cost values for a few cards and introduced a few more food bonuses. This has helped increase the # of cards that players can typically catch during a turn and speeds up the game.
  • Reduced number of ”resets”: There is one “reset” card in the game (Ohno Oogly) that forces all players to discard all Monsters from their Zoos. Essentially this is a game reset since everyone needs to rebuild their Zoos from scratch. While this is a great strategic card that can make a huge difference in the game, playing the card too many times during one game will cause the game to drag out and become less fun. I’ve reduced the amount of cards like this in the game to keep the game progress steady and rapid.
  • Introduced new card combinations: I added a few more cards that have good synergy with other cards – which should offer some extra strategic depth along with fun combos.

Thanks everyone who has playtested Monster Zoo thus far. I think you’ll like the new revised version.

Monster Zoo: Blind Playtest Jitters

A month ago, I started blind playtests for Monster Zoo.

Before this, I was present at all playtests. I could explain rules in person, answer any questions that came up, and generally guide the gameplay to a smooth experience. There were major benefits to doing these playtests in person. If the game broke down in a session, I could quickly tweak the game and everyone could play another round. Players could ask how a specific card or action could be used. The immediate feedback and prototyping cycle was great.

Based on all the playtest feedback, I continued to improve the game little by little. (The advice from this post was extremely useful during the feedback process.) After a few revisions, I decided to move onto blind playtesting.

Blind playtesting is nerve-wracking for a designer. During a blind playtest, you provide the physical game to a tester, and without any additional input they go off to play the game. You can’t help them with the rules or answer any questions. You assume that all the work you’ve put into the game has created something fun and playable. But you never really know.

So after deciding to move on to blind playtesting, I packaged up the most recent version of Monster Zoo and sent it off to my friend in San Diego. I purposefully didn’t give him any details regarding the game. His job would be to introduce Monster Zoo to his gaming group and give me feedback.

And this is when the nerves start to kick in.

I started to wonder if the game was even playable, if the gaming group would enjoy the game enough to get multiple plays in, whether or not the rules were clear enough, etc.

After a few weeks of trying to ignore these nagging thoughts, my friend came back to me with tons of feedback. It was a success!

Turns out my friend and his gaming group had been playing Monster Zoo daily for a few weeks.

Here’s the feedback I received:

  • Really enjoyed the game, played it multiple times daily.
  • Different groups enjoyed the game, introduced it to several different types of players.
  • Rules were good. Easy to read.
  • Liked the relatively short play time.
  • Good variety between plays.
  • Good variety of cards.
  • Liked the theme.
  • Liked the card names.
  • Did not run into any game breaking issues.
  • A few of the cards were overpowered, everyone wanted them.
  • One “broken” card in particular caused score spikes.

The “broken” card that came up in the feedback process was “Wild Zoo”:


This card is an Event card that affects all players when it is drawn. In a few cases, when this card was drawn, there were players with really high scoring Monster cards in their hand. This then created a situation with huge point swings that felt a little too random.

There are other Event cards that allow players to move one Monster into their Zoo, so reducing the effect of “Wild Zoo” would make it a redundant card. For now, I’m removing this card from the game as I rework the effect.

Overall the feedback was extremely positive, much better than I could have hoped for. It totally floored me that a group of gamers with no real connection to me was playing Monster Zoo daily. Most of the new players introduced to the game had no problems picking up the game and playing within a few rounds. Players seem to be enjoying the combination of a light deck building game with strategy around managing the cards in their Zoo.

Excel and Google Docs Spreadsheet Tips for Game Designers #2

Last month I wrote a post describing a few uses for spreadsheets in game design. Based on the feedback, I decided to write a quick follow up on how I’ve been using spreadsheets in my own game design.

I’ll be using Monster Zoo to illustrate my examples. Here’s a link to the public spreadsheet of cards @ Google docs.

Identifying Possible Balance Issues

Monster Zoo is a deck building game consisting of over 180 cards, with more than 40 unique cards. Keeping all those cards in balance is really important, because if one card is extremely overpowered or underpowered, game play fun is effected.

So how do you understand whether or not your game is balanced? My approach has been to create a cost curve for all cards (refer back to this post for more on cost curves). This allows me to easily see whether or not in general Monster Zoo is balanced.

cost curve

You can see that most of the costs and benefit numbers are packed closely together. Cards that cost 3 points have a benefit of around 2-4. Cards that cost 4 points have a benefit of around 3-6. Etc. This looks decently balanced to me.

But what about individual cards? While the game overall may look balanced, there still could be specific cards that are broken.

To take a look at individual card balance, you can chart out costs and benefits by each card.

Screen Shot 2013-03-26 at 3.26.03 PM

Now I can easily see that “Fifi Oogly” might be out of balance with the rest of the cards. That’s a card I need to keep an eye on in playtesting. One thing to keep in mind is that everything does not need to be perfectly balanced. It all depends on what type of game you are designing. Some games need to be much more balanced, while other games might purposefully be designed to have a swing mechanic or some unbalancing feature.

Faction / Group Design

In Monster Zoo, there are three types of Monsters: Boogly, Oogly, and Zoogly.

Each of these Monster types represent a different feel and mechanic in the game. Boogly monsters help players draw faster and perform more actions. Oogly monsters help players acquire more resources and builds up in power over time. Zoogly monsters help players move monsters around and are otherwise utility type cards.

Along with different mechanics, I wanted to give each of the Monster types it’s own unique cost “feel”. Since Boogly monsters were all about being faster and drawing more cards, I thought it would make sense for Boogly cards to cost less in general. This would help players get a sense of speed and action.

For Oogly cards, I took the opposite approach and created more higher cost Oogly monsters. So this gives the Oogly monsters a slower feel, but more impact.

Zoogly monsters are more about utility, so the cost is more evenly spread.

Here’s how it looks in the current version of Monster Zoo:

Screen Shot 2013-03-26 at 3.46.46 PM

Charting out the number of cards, the card cost, and the card type gives me a quick look at how well I’ve differentiated the Monster types. You can see that there are more cards with lower costs for Booglies and more cards in the higher ranger for Ooglies. Zoogly monsters are relatively mixed.

So even though the costs for each Monster type are very different, we know that each card is still balanced (from our cost vs benefit chart above.)

Modeling Gameplay

What if you want to get an idea of how the game plays over time? You can model out basic turns by calculating values for typical actions: catching monsters, food in hand, deck value, etc.

Screen Shot 2013-03-26 at 4.07.24 PM

This shows me that Monster Zoo game play is linear, throughout the game you gain Monsters at the same rate (obviously this depends on which Monsters you are catching). So decisions you make in the early game and the late game are generally just as impactful.

But what if I wanted to make the late game more swingish, with larger points and bigger rounds?

I could change a few values and end up with something like this:

Screen Shot 2013-03-26 at 4.14.28 PM

This type of gameplay has more cards at play in the later game and rounds in the late game are more important. More monsters are caught and each hand has a higher food value.

Take a look at the public spreadsheet if you want to play around with the values and see how the chart changes.

Monster Zoo – Deck Building & Zoo Management


Monster Zoo is a game I have worked on for the past few months. In the game, players take on the role of new Zookeepers, trying to fill their empty Zoos with Monsters from the wild. (The same theme as Monster Zoo: Draft)

The game’s main mechanic is deck-building, similar to Ascension or Dominion, but with much more interaction and a bit of what I’m calling “zoo management”. As you acquire more cards and start to build out your deck, you’ll also move cards from your deck to your Zoo. While cards are in the Zoo, you’ll earn points, but you expose yourself to other players who can steal cards from your Zoo. So there’s a back and forth strategy between building up your Zoo or making your deck stronger.



Here’s the PNP version, so you can try it out at home:

I’ve already started to play test the game and so far the response has been very positive. I’m excited to develop this game fully and get it out to Kickstarter later this year. Keep an eye out for that!

Monster Zoo is a deck-building zoo management card game for 2-4 players that lasts about 30 minutes. I’m really looking forward to your feedback.


Monster Zoo: Draft – Version 0.1

Monster Zoo: Draft is a card game that I have been working on for the past month. It’s a lighter, easier to play game with the same theme as it’s older brother Monster Zoo. In the game, players take on the role of new Zookeepers, trying to fill their empty Zoos with Monsters from the wild.

The game’s main mechanic is card drafting (inspired by 7 Wonders & Sushi Go). Players are dealt 7 cards to start the game. Each turn, all players choose 1 card from their hand, plays the card, and passes the remaining cards to the player on their left.

As cards go around, players will be trying to complete sets of Monsters and prevent other players from doing the same. You can try to build a large set for a ton of points, but run the risk that another player will stop you from completing your set. There are also special cards that add deeper strategy elements. The game should feel light and fun to play with a wide variety of ages and gamers.

I think it’s in a good place for playtesting now, so here’s the print-and-play version:

Monster Zoo: Draft is a light card drafting game for 2-5 players that lasts about 20 minutes. I’m eager to hear your thoughts!

Using Cost Curves to Balance Card Costs

In Monster Zoo, I try to keep cards balanced according to their cost to acquire. Cards with stronger effects typically have higher costs and weaker cards have lower costs. However, after a few rounds of play testing Monster Zoo, I realized that some cards in the game were out of balance. A few cards felt really strong and could easily sway the game towards a player’s favor quickly. And a few cards seemed really weak, when played they had little effect on the game or felt too expensive to acquire.

One of the best discussions I could find on the topic of balance is a lecture from Ian Schreiber on Transitive Mechanics and Cost Curves. In the lecture, Ian talks about breaking down all the individual effects of your game into two things: costs and benefits. By doing this, you can get a sense of how balanced all the components of your game are relative to each other. If a particular item has a much higher benefit to cost ratio than other similarly costing items, then you know something is out of balance.

Here’s how I went about applying this principle for Monster Zoo.

First I broke out every single card into it’s individual effects. For example, the card Whompo Boogly has the following stats: “+2 Food. Zoo Effect: Draw an extra Card this turn.” This card has two unique effects:

  • Food Gained
  • Zoo Effect that Draws Cards

After identifying every effect, I then gave a rough benefit score to each effect in relation to other effects. Then I added up the value of every benefit per card, giving me a benefit total score.


Now I have a rough cost / benefit comparison for each card. But it’s hard to really get an idea of where some of the cards might be unbalanced.

This is where a cost curve (basically a visual representation of your cost / benefit) comes in handy. Charting out the cost / benefit of all the cards gives me this:

cost curve


With this, I can see that there are a few cards that are unbalanced in a few ways:

  • There are cards with a cost of 3 that have less benefit than some cards with cost of 2. (Underpowered)
  • There are cards with a cost of 5 that have less benefit than some cards with cost of 4. (Underpowered)
  • There are cards with a cost of 4 that have more benefit than some cards with cost of 5 or 6. (Overpowered)
  • There are cards with a cost of 6 that have much higher benefit than the natural cost curve. (Possibly Overpowered)

Let’s look at two specific examples.

One of the cards that seemed overpowered in play testing was Fifi Oogly. This card has the following stats:

  • Cost: 6
  • Benefit: 9
  • Gain +2 Food
  • Monsters cost 1 less Food to catch this turn.
  • Zoo Effect: Monsters cost 1 less Food to catch this turn.

Based on the cost curve, you can see that this card has much more benefit than it’s cost. So we have two options here, we can increase the cost or we can reduce the benefit. I happen to think it’s a fun card to play with, so I’ll likely test increasing the cost.

Here’s another card, Yummli Oogly. In play testing, this card seemed weak and no one really wanted to acquire this card. Here are the stats:

  • Cost: 6
  • Benefit: 5
  • Double all Food gained this turn.

While this card seems like a really strong card, it definitely is below the curve. If you compare it to a card like Chunky Oogly which has the following stats:

  • Cost: 3
  • Benefit: 4
  • Gain +2 Food
  • Draw an extra card this turn

You can see how Yummli Oogly is fairly weak, on the cost curve it is seriously below everything else with a cost of 6. Having 2 Chunky Ooglies would be much better for the same cost. In this case, I might add an effect to Yummli Oogly to get it back in balance.

Some guidelines for creating your own cost curve and using it to balance your game:

  • Break down all effects into individual unique effects
  • Assign a relative benefit value for each effect
  • Create one cost value for each item
  • Compare the cost / benefit to understand balance

Excel and Google Docs Spreadsheet Tips for Game Designers

As a new game designer, I’m finding that there isn’t much information around game design or game balancing. Seems like most of us are starting off with paper & pen, whipping up a quick prototype, and then immediately playtesting.

I started Monster Zoo off the same way. However after a few rounds of playtesting, I realized I need something that I could use to see how the game looked from an overview. Enter Excel/Google Docs.

Here are a few of the tricks I’m using to make my life easier as a game designer.

Card Files

First off I start with a basic spreadsheet of all the cards in the game (card file):

card file spreadsheet

The card file contains everything about the game at the component level

  • All the cards
  • Types of cards
  • Costs
  • How many copies in the deck
  • How many copies in a player’s deck
  • Card strategy

The card file makes it easy for you to make changes to the game and gives you quick sense of how your game looks. But what if you need more detail around specific card types? Maybe you are interested in knowing if a certain card type is out of balance?

For example, in Monster Zoo, there are three types of monsters: Ooglies, Booglies, and Zooglies. How can I tell if there are too many Ooglies? Or if the cost of Ooglies are too high compared to Zooglies?

Pivot Tables

This is where Pivot Tables can help. Pivot Tables provide you with a way to summarize your data, so you can easily understand what is going on. It’s great for getting an idea of how your initial game balance looks.

Let’s get back to answering a few of my questions about Monster Zoo. How can I tell if the three monster types are balanced from a cost perspective?

I can create a Pivot Table with the following settings:

  • Rows: Monster Type
  • Values: Cost (Average)

Monster Types Cost Average

This shows me that all three monster types are relatively balanced – the cost average ranges from 3.9 to 4.2. Pretty close.

Now what if I want to know how the different card strategies are distributed throughout the game? Monster Zoo generally has three basic strategies: card advantage (you draw more cards than other players), point advantage (cards help you gain more points), or resource advantage (you are able to catch more Monsters than other players). In general, I want these all to be relatively balanced, but I’d like to have less card advantage in the game because that tends to have an effect where players keep drawing cards but nothing new is happening.

So let’s take a look.

I create a Pivot Table with these settings:

  • Rows: Monster Type
  • Columns: Card Strategy
  • Values: COUNTA

Monster Type Card Strategy

I can see that the game is more heavily skewed towards resource advantage and points. Which for now is good.

Calculating Draw Probabilities

One of the bigger balancing issues I had with Monster Zoo is trying to figure out the right number of each card type in the central deck. Too many of one type of card and the game didn’t see enough variety. But too little of one type and it possibly could bog down.

This is where the function HYPGEOMDIST can help. HYPGEOMDIST represents the hypergeometric distribution  This function helps you understand the probability of a certain card being drawn from a deck.

For example, I used HYPGEOMDIST to calculate the probabilities of each card type showing up in the first 5 and 10 cards drawn.

card distribution draw

This shows me that it is almost guaranteed to have a Monster card show up on the first turn draw from the central deck. There’s only a 40% chance that a Visitor card will show up on the first turn, but by the time 10 cards are drawn, that chance goes up to 65%.

The function is: H (n) = C (X, n) * C (Y – X, Z – n) / C (Y, Z)

  • C stands for Combination
  • X stands for the number of a certain card that you have in the deck.
  • Y is the number of cards in the deck.
  • Z is the number of cards you are drawing.
  • N is the number you are checking for

Both Google Docs and Excel have a shortcut function called HYPGEOMDIST to make the calculation easier.

Modeling Resource Gain

Another thing spreadsheets are good for are modeling game progression. For example in Monster Zoo as you gain cards and shuffle them back in your deck, you are changing the distribution of resources in your deck. As the game designer, it’s good to understand how the amount of resources are changing because this effects what your players can afford each turn.

Here’s an example model of 20 turns of Monster Zoo:

monster zoo resource model

This shows me that over time, most players should be able to afford more costly Monsters. If I end up modifying the average +Food on a Monster card, you can see how that affects a player’s buying power in later turns.

monster cost

I hope I’ve helped show off some of the interesting game design tasks a spreadsheet can help you with. Looking forward to hearing some of your tricks and tips.

Game Design Theory: Luck and Skill

As I set out to design my first game (don’t worry I’ll talk about it soon), I spent a lot of time thinking about luck and skill. I am generally a fan of very strategic and skillful games, ones with very little amount of luck. But in designing this game, I knew I wanted to make it accessible to a variety of players – specifically kids and casual gamers.

There is a very interesting lecture by Richard Garfield discussing the topic of luck versus skill in games:

The NYU Game Center Lecture Series: Richard Garfield from NYU Game Center on Vimeo.

In the lecture, Richard highlights the benefit of luck in game design. Games with luck tend to be more engaging because even lower skilled players have a chance at winning.

A few of the first versions of my game were very strategic and limited the effects of luck. As I continued to playtest, it was obvious that introducing more luck into the game made it more fun and easier to play. For games that are targeted to a more casual audience like family games, I think involving an amount of luck is a good thing. To add more depth to the game, skill should allow players to influence the impact of luck.

What do you think?