Tag: combat mechanics

Designer Diary: Corrupted by Ruin #3

I think I’ve figured out a workable system for combat in Corrupted by Ruin. The biggest constraint is that it must be fast and uncomplicated since each hero incursion potentially initiates multiple encounters. Forcing players to go through the same actions many times will get repetitive. The natural model for quick, simple combat is an idle system where the player sets up the battle and lets it play out. Just think of Loop Hero, where the player speeds through hundreds of fights in a run. So I decided to have a similar system, where combatants have health bars and cooldown timers and attack random targets.

Idle combat comes with its flaws. My chief concern was that it would muddy the differences between different monsters, which happens in “Hero’s Hour.” I think I can get around this by limiting the number of combatants on each side to eight, but this still leaves the question of how to distinguish monsters from each other without the ability to select actions. And I think I have found the answer – a variant of my idea to incorporate Spirit Island threshold mechanics, but one that treats monsters and heroes as asynchronous element converters.

Here is how my new system works. Each creature has two or more actions, each with a priority. It goes through its list in order until it finds something it is capable of doing. Each ability may have an elemental cost and might produce some elements. However, these are available to any creature on either side of the fight – for example, the heroic cryomancer might use the water element your slime produced to boost a spell, or your salamander might benefit from the enemy flame knight’s fire generation. Each battle becomes a converter-based economic game.

One implication of this system is that speed matters a lot. If you see a slow hero that needs fire to be effective, you can counter it with a faster monster that also uses fire because it is more likely to get the element first. Or, if there is a quick hero that consumes water, you might avoid using water monsters.

Another neat thing that I can do with this system is to change the behavior of creatures depending on what is available. For example, maybe there is a troll that typically guards other monsters, but if you flood the room with psychic energy, it goes berserk and starts attacking. The player can then use elements to choose a strategy for their side and manipulate their enemies.

One concern with any combat system based around synergies is that players will get locked into a pattern. If a combination of monsters is good, why not just use it every time? I predict that my elemental conversion system will avoid this because even the same team of monsters will behave very differently depending on the enemy heroes they face. Furthermore, even though you fight the same heroes in multiple rooms within a single incursion, the rooms can also consume and produce elements, which should be enough to shake things up.

Designer Diary: Corrupted by Ruin #2

I spent the last week at a game design retreat, and among other things, one game I tested was “Corrupted by Ruin.” I don’t have a digital prototype yet, so I printed out some tetrominoes and monster cards and had people play it as though it were a board game.

There are some pretty significant differences between digital games and board games. Some games that work great in the digital realm fall flat in the real world, and some things don’t make the transition in the other way very well either. Still, paper prototyping is a great way to validate an idea, and it is a good sign if something works well even without a machine.

While playtesting, I realized that the triggering mechanism for an incursion makes a big difference in how it feels. Traditionally in tower defense games, the player alternates between constructing defenses and operating them (actively or passively) against regularly scheduled waves of intruders. For example, in “The Last Spell,” the player builds structures and upgrades their heroes during the day and then deploys them against the monsters that attack every night. I initially approached my design this way since it is about defending a dungeon against heroes.

The problem is that this leaves the player very little control over where the heroes enter the dungeon. A big part of the game is engineering encounters to maximize the effectiveness of the monster and room combinations. If the heroes can enter the dungeon anywhere, the player has little control over their path. Seeing where the heroes enter ahead of time doesn’t help much either because the player can’t rearrange their rooms to account for it.

So instead, I tried letting players trigger the incursions. I added “staircase” tiles around the map, and whenever a player would connect to a staircase tile, heroes would invade. The player’s incentive to go after staircases was that defeating heroes was necessary to win. The resulting game felt much more interesting to me. The player is still playing defense, but now they control when and where they fight the heroes.

Roguelike games tend to have a proactive aesthetic, where the player is constantly advancing spatially towards a goal. Reactive gameplay clashes with this. I tried out “Tower Tactics: Liberation,” a tower defense roguelike, and found this contradiction to stand out. You move from place to place, and in each location, you set up towers and defend against waves of enemies, but the contrast between the map movement and the lane defense is a little jarring. By flipping the script so that the heroes react to the player’s incursion, I hope to align the high-level gameplay aesthetic of conquering land after land with the lower-level conquest of a single kingdom.

Giving the players complete control of hero incursions also has implications for what happens when the heroes invade. Deterministic combat allows players to calculate the exact results of triggering a battle rather than relying on their heuristics. I want to avoid this because it is tedious for the player. Also, with more control over the path the heroes take comes the obligation to make the associated decisions more interesting. I think my current combat system is too plain to justify this, so I am starting to think about more interesting mechanics for combat. I will most likely want a puzzle of some sort.

Another problem that I solved through paper playtesting was how to handle monster recruitment. My previous system involved buying monsters from a pool of available ones, with new monsters unlocked by building specific types of rooms. That has three problems: First, it obligates the design of a matching room or monster even when it doesn’t necessarily make sense. Second, players already draft rooms, and doing the same for monsters feels repetitive. Third, it doesn’t interact very much with the tile-placement mechanics that are central to the game.

The solution turned out to be very simple – monsters, like gold, start each level embedded in the map. When you cover them with a tile, they join your dungeon. Now I can design monsters independently from rooms and even associate them with map types, and monster drafting interacts with room placement to enhance both.

To “mine” monsters out of the ground implies that monsters are a finite resource. Limited upgrades for monsters also make sense since they feel less generic than they would under a drafting system.

Designer Diary: Corrupted by Ruin #1

I’ve started working on a new computer game. I initially envisioned it as a cross between Dungeon Keeper 2 and FTL; you build a dungeon, gain monsters, and move them around your dungeon to respond to adventurers that try to invade. By surviving over several rounds, you gradually corrupt and take control of the land you are in, and a run involves corrupting several such lands.

In contrast to Icewords, for which development was very ad-hoc, I’ve decided to plan this game out in advance. I am making a game design document in as much detail as possible to have a clear picture of where I am going. I am also experimenting with test-driven development, using the Godot unit testing framework WAT.

Understanding the genre expectations of players is crucial when making a game. You don’t have to adhere to all of them, but it is easier for players to understand a game when they are already familiar with aspects of it. Dungeon Keeper 2 is the best example of the genre I am targeting. Some of its features that I see as essential are building a dungeon out of different types of rooms, attracting a variety of monsters to your dungeon, and using those monsters to fight off heroes that try to invade. Mining for gold while building tunnels is another iconic mechanic that would be good to replicate.

I decided to start my brainstorming with the concept of rooms. A large part of the progression that I envision in my game comes from unlocking, building, and upgrading many different types of rooms. Each room has a different effect and spawns a unique minion type. Some rooms can also transform when connected to others, an idea I got from Loop Hero. For example, placing a Library next to a Graveyard transforms it into a Haunted Library. Players like having little secrets to discover.

My initial vision for the rooms was as square tiles placed in a grid, like in Galaxy Trucker. When designing any spatial game about building something, I always ask: “Why does it matter where I place things?” In Galaxy Trucker, many threats come from a predictable direction and are more likely to occur in some rows or columns than others. While this makes sense in space, I didn’t see an obvious way to do something similar underground.

There are all sorts of ways you can make positioning matter based on the abilities of certain rooms. I object to relying exclusively on room abilities, however. It places a burden on new players; to make intelligent decisions about placement, they need to learn the nuances of each room. Therefore their heuristics are not transferable when exposed to new room types. I wanted to provide a reason to put a room in a particular location independent of what the room did.

I decided to try using tetrominoes instead of uniform square tiles. Most games that deal with tetrominoes ask questions about how efficiently they tile the board and what is on the spaces they cover-up. The latter focus is perfect for a game about building a dungeon because it is naturally suited to mining mechanics: you can print resources on the board for the player to harvest by covering them up.

Cover-up mining is probably enough to justify tetromino placement, but I wanted to make efficient tiling a focus too. In Dungeon Keeper 2, you gain a mana resource based on the area of your dungeon. In thinking about implementing a similar system, it occurred to me that rewarding the playing for dungeon area and penalizing them for dungeon perimeter naturally incentivizes efficient tiling. Mechanically, the player gains energy for each tile in their dungeon and loses it for each adjacent empty tile. Thematically, rooms generate mana and radiate it off into the environment. Mana thus obeys similar rules to real-world heat, which I like.

Such a system gives players two contradictory guiding reasons for tile placement. They want to spread out to harvest resources on the map, but they want to stay compact to minimize mana radiation loss. On top of this, they need to consider room evolution and any room abilities that care about proximity or adjacency. Overall, I think this gives enough reasons to care about where they place their rooms to make tile positioning meaningful.

At this point, I decided to try out unit testing in Godot while implementing classes to handle tetromino rooms and maps. I tried using GUT first but didn’t like that I couldn’t use arguments in my constructors with it, so I switched to WAT. I also prefer WAT’s integration with the editor over GUT’s requirement that you launch a scene to run your tests.

The biggest unexpected thing I learned is that unit testing is great for giving you feedback without having to implement example scenes. Previously, when making games in Godot, I would rush through a slapdash setup to get something I could play, leading to messy code that I would have to refactor. Psychologically, we want to see results for our work, and it is hard waiting for thousands of lines of code before you see anything happen – plus, you are almost sure to have an error somewhere. But being able to write a unit test and then immediately see results reduced this need a lot. Unit testing doesn’t just help you catch errors; it also helps you stay motivated.

Combat is the next consideration, which I am still debating. The planned structure of the game is that you cycle through the phases of building rooms, preparing for the heroes, and fighting the heroes. At first, I imagined this working like FTL boarding mechanics where monsters and heroes in the same room will automatically fight each other, and the challenge is allocating your monsters. Heroes would enter the dungeon from doors that lead out, so the layout would influence where threats appear. Battles would happen in real-time, perhaps pausing to cast spells or issue orders.

However, I’m not sure how interesting I can make that without becoming inaccessible. Crew combat is simple in FTL because you have to manage other things simultaneously, like weapons and power allocation. But if the focus is on fighting alone, I’m not sure it would be interesting enough to justify the phase. The issue with idle combat is that aside from the choice of where to allocate forces, the player has very little to do. Also, the idea of independent heroes invading from many different points feels off; capturing the traditional feel of a party venturing through a sequence of encounters would be better.

Another problem with real-time combat, in general, is that it severely limits the feedback you can give the player about differences between units. For instance, I recently played a newly released game called Hero’s Hour, where you recruit armies comprising many different types of units. However, combat involves a real-time battle where your entire army fights the enemy army, and it is difficult in the chaos to tell how each type of unit differs from the rest. I have observed this with RTS games as well; real-time combat smooths over the unique properties of each unit. I want the different monster types to have personalities, not blur together into generic minions. Therefore, I realized that I needed to have turn-based combat.

Currently, I am considering a system where a single party of adventurers encounters one room of your dungeon at a time, and you deploy monsters (and traps and spells) to that room as though you are playing cards. I was thinking about a turn-based idle system where heroes and monsters alternate dealing their damage, but that adds a lot of time to the game, and I’m not sure how your choices would change between combat rounds. If a spell is good to play, wouldn’t you spam it? And if you can’t, then why have multiple turns? Instead, my current vision is that there is one round of combat in which you play your cards and hit resolve, and then the heroes progress to the next room.

I’ve been playing a lot of Spirit Island lately, so it occurred to me that the power thresholds mechanic would work well with such a combat system. Each room and monster in the room provides elements, and each room, monster, trap, and spell has two effects – a weaker default effect and a better effect that applies when used in a room with the matching elements. I still need to figure out what makes the most sense thematically for how traps work.

I love reading or listening to post-mortems and designer diaries, but my games often have few records about why I made the choices I did or what issues I encountered. I think recording my reasoning as I go is valuable not just for looking back but also to help understand my design choices as I make them, so I will make more of an effort to post about it here.

Granularity and Combat Mechanics in Tactical CCGs

I have never played Hearthstone, but I have played some of the games it inspired. Back when its servers were still active, I remember enjoying Duelyst a lot, in particular. Duelyst was an online CCG where players drew creatures, items, and spells and played them to a grid. Essentially, Hearthstone but with spatial positioning. While I don’t often care much about graphics, I found its pixel art style one of its most compelling features.

Recently, partially out of nostalgia for Duelyst, I tried out a similar game called Cards and Castles 2. I stopped playing after only a few minutes because I found the granularity of the combat mechanics to be unbearably high. Just as with Duelyst, each creature has an attack number and a health number. Attacking lowers your target’s health number and also prompts them to counterattack. However, the range of numbers used commonly goes into the forties and fifties. Worse, to see the current attack and health, you have to mouse over a unit, making it very difficult to understand each creature on the board at a glance.

Funnily enough, Battle for Wesnoth has similar combat mechanics and granularity, but I don’t mind it in that game. I think this is due to expectations. Battle for Wesnoth is a turn-based strategy game often played against the computer, so you expect to consider each move carefully. Cards and Castles 2 presents as a CCG suitable for quick matches against other people, so the amount of processing required to understand each unit is more noticeable. Duelyst, by contrast, keeps most numbers under ten and displays them clearly beneath the creatures.

The moral of the story is that large numbers make it harder for players to grasp the game state because they make the arithmetic harder and less automatic. Another related issue with Cards and Castles 2 is that the abilities of the cards use percentages; “this unit gets 20% damage resistance” or “this unit takes 70% less damage when attacked from the front.” A percent value works for probabilities but serves as a barrier to understanding when it requires actual multiplication. The only percentages that most players can multiply without effort are 50%, multiples of 100%, and (to a lesser degree) 10%. Abilities phrased in terms of small integers are a lot easier to grasp.

In contrast to board game design, I think it is tempting when making computer games to assume that complex calculations carry no cost because the computer is performing them. But this isn’t entirely true – even though the computer can crunch the numbers, the player may still want to understand what they mean.

After my disappointment with Cards and Castles 2, I still felt nostalgic for Duelyst, so I tried another similar game; Stormbound. I was pleasantly surprised. The game takes place on a four-by-five grid where the objective is to damage your opponent by marching a certain number of units to their side of the board. Unlike other tactical CCGs, it is an auto-battler – you cannot issue commands to your pieces once placed; they move forward by themselves every turn.

Another unusual feature of Stormbound is the deck size – 12 cards. Most CCGs have decks of 30-45 cards, but Stormbound instead recycles cards so that you have no discard pile. You can have exactly one copy of each card in your deck and see all of them several times each game. Lucid works the same way, so I am well acquainted with its advantages. Among other things, this makes constructing a deck much less daunting since you only have twelve choices to make and don’t have to worry about how many copies of each card to include.

The most novel feature of Stormbound for me was the stats of its armies. Instead of the typical Attack/Health, each card has Strength/Movement. The first number is how many units you gain when playing the card; the second is their number of immediate moves.

When two opposing armies fight, they both lose an equal number of units such that only one remains. I have not seen combat mechanics of this mutually-destructive sort before; the closest thing I can think of is combat in Neptune’s Pride. My natural inclination before seeing Stormbound was that it wouldn’t work because it eliminates the possibility of one side gaining an advantage through combat – for each unit you destroy, you have to sacrifice one of your own, so what is the point?

I think I understand how Stormbound makes it work, however. Most units created are just a byproduct of effects that occur when you play cards. For example, playing a card might deal one damage to every unit in a line AND create a two-strength army at the origin of the line. Some units do have persistent special effects, but most do not. It doesn’t matter that your units mutually annihilate in combat because the game is all about where you play your cards.

The idea of having one number combine attack and health doesn’t seem quite so radical to me anymore. In Duelyst, combat hurts both parties as well; the only difference is that both might survive. It might be different in a multiplayer game where both suffer to the benefit of the other players; then again, this is already what happens with more than two players.

I don’t recommend Stormbound as a game. It allows players to level up their cards to make them stronger, which means that a player who has spent more money might have a better deck than a new player even with the same cards. But it has does have some unusual mechanics worth checking out that challenge the orthodoxy on digital CCGs.