Friday, May 20, 2016

[IndieDev] Eon Altar's Team Turn Based TRPG Combat Design

Eon Altar's combat systems have been iterated on over the past 2 years pretty significantly, but the core tenets have stayed pretty constant. When we first set out to make this version of Eon Altar, combat came out of the gate relatively early in the process with a very strong design vision set by Christoph Sapinsky (@XophRA on Twitter). Later on after Christoph moved on from the team Scott Penner (@AltheusStone on Twitter), our lead designer, continued iterating on the system. Throughout the entire process, I've definitely made opinions and suggestions known.

Combat today is a team turn-based affair, with each player having a strong class identity and an array of unique-to-the-character powers they can pick and choose from each turn. Being able to take your turns simultaneously or in any order you choose allows for fast paced combat that you can slow down and plan at your choice. A clear energy economy for spending on bigger powers gives an ebb and flow over the course of a single fight. Many powers have secondary effects that make each one worthwhile in different situations. Outside of combat itself, character progression in the form of upgrading existing and unlocking new powers, stat boosts, weapon/armour upgrades, and consumable items help round out the longer planning game.

As evidenced by watching people play at PAX East, we've certainly succeeded in making an engaging, tactical combat system. But where did we start from, and why have we made some of the decisions we have along the way?

Original Vision

We had a few design goals we needed to keep in mind as we created combat and evolved it. The current system bears many of these out--though to a lesser degree than we'd like for some, admittedly. Some of the vision we've had to leave due to just not being able to build the tech, or as we built the game, that aspect of the vision came into conflict with providing good game play.
Letting smart player decisions really maximize their results in battle, including proper physical placement, equipment management, using and progressing individual abilities, and cooperation with other players. Epic battles should engage players with strategy that requires group discussion.

Fast Paced
Not every battle needs to be epic; most fights will be fast and brutal and serve to contrast the fewer, more strategic fights. Players should feel that once they've committed to an action that the result is quick. Turns will be team-based, so turns go by quickly and players won't have to wait long to make their next decision.

When the time is right, we will reward players with a display of how bad-ass their character has become. Some monsters and battle ends should trigger "death blows"--special animated sequences. These cinematic sequences will be rare, but valuable interruptions to the regular flow of an otherwise fast-paced combat experience.
From the start, we had the team turn-based tactical combat vision. It was important to us that combat was fast and fluid, but you could take the time to make nitty gritty decisions if you really wanted to (or in the case of some combats, need to).

Vision Variation

I'm of the opinion that we succeeded in spades with the tactical and fast paced aspects of the vision, but some parts of the vision had to be left behind.

One of the biggest omissions is probably the Cinematic portion. By the time we got combat in a nascent working state, we realized that interrupting the flow of combat was going to be difficult to do in a way that wasn't frustrating to the players. Since turns are simultaneous, when a player went in for a critical hit, if we did a cinematic zoom it would interrupt the other players' targeting. Similarly, if three enemies are attacking simultaneously, and one of them gets a critical and we did a zoom, players wouldn't see the other enemies attacking, which is problematic from an informational standpoint.

I believe one day we'd still like to do finishing blows for the end of combat, but given everything else we needed to get running, it fell down on the priority list until it was cut for our current release. Something to revisit if we do well enough to release more seasons.

Cinematic has evolved since to be more about ensuring powers look and feel great. Fireball, Blood Rage, and Shield Slam are all incredibly satisfying powers to use because they look powerful. It's not just the numbers, but the visuals and sounds enforcing that.

Powers and Positioning

One of the things that I would've liked to have more of from our tactical paragraph is physical positioning. To be sure, physical position does matter. If an enemy attacks you from behind, they have an accuracy bonus; if you're too close an ally may accidentally nail you with a fireball or a cleave attack; and enemies can "block" you from making melee attacks on their friends behind them as a sort of "melee line of sight" deal.

But each action in combat is actually a series of actions, which makes having fine-grained control over positioning difficult. You decide what the top-level action is going to be, and then the action itself performs a series of sub-actions that's entirely AI controlled.

Basic Turn Flow; Thinking, Targeting, and Executing occur on the main game while Deciding occurs on your Controller App.
A simple example of this would be Muran's Aetherbolt. You select your target, and decide you want to Aetherbolt them. The Aetherbolt action has two sub-actions: Move, Attack. The Move sub-action calculates the furthest point you can be from the target and still hit them and moves you to that location. The attack sub-action actually performs the ranged attack.

A more complicated example would be Marcus' Lance Assault. It has six sub-actions: Disengage, Move to Target, AoE Smash/Knockback, Find Random Enemy Target, Move to Target, Attack. This power has two move sub-actions in it, letting Marcus rip around the battlefield, but you don't know where you'll end up.

Because the AI is doing the movement for you, it's doing its best to guess where you should be and makes the attack. But you don't have much direct control over your position or facing when the attack is complete.

The benefit to this is each turn is important; we can ensure that nearly every turn you're doing something that has direct impact on the fight. While you can decide to just move to a specific location, most of the time you want to be doing actual actions and rolling movement into those actions allows you to spend more time doing and less time jockeying. Being too far away to do anything at all isn't something that occurs most of the time if your party is moving together as a group (if you have a laggard, well, your marching order may need work).
The left is what a Fireball would've looked like for damage areas early in development. You can see enemies acting as physical barriers. Today, it just hits everything in the AoE. However, the left side is still how we determine if you can attack someone with via melee.
The negative is, as mentioned before, lack of control over various sub-actions, including positioning. Because of that lack of control, we can't enforce too many positional requirements or it will become an exercise in frustration for players. Over the course of development, we've relaxed positional restrictions over time, allowing for ranged attacks and AoEs to go through people, deciding not to implement D&D-style attacks of opportunity, and allowing any position that isn't directly in front of someone count as "flanking".

Measuring via play testing, this relaxation has noticeably reduced player confusion and frustration. Some of it was figuring a way to communicate this information (and for the record, I don't think we're communicating the melee line of sight restriction at all currently), but a lot of it was just...the restriction wasn't fun. Players like having options, and many of the restrictions reduced what options you had on a turn-to-turn basis.

Part 2 Coming Soon

This post I talked about the original vision and what we've managed to keep from it and what we've missed, as well as the combat loop from a single-turn perspective. Part 2 next week I'll talk a bit more about the full combat loop, as well as the longer multi-combat loop.
#IndieDev #EonAltar #GameDesign


  1. Thanks for the shout-out. Don't forget to talk about context based aspect of the system, it is something that snuck up on me, but turned out to be an essential aspect of Scott's vision.

    1. Definitely a good point! Something largely driven by our UI capabilities and the sheer amount of powers we could (and do) have. I'll have to discuss that in more detail!