Recalling the Leviathan Axe

~After spending the last several years working on God of War, I was trying to figure out what to do with a sudden surge of free time. After talking about it with several other designers on the project, I thought it might be nice to just ramble on about some of the stuff I spent the last 5 years of my life working on. So full disclosure: there's a good chance nothing here will be of interest or use to anyone...

With that said, the first mechanic I wanted to talk about was something that ended up being a pretty unique and well regarded mechanic - recalling the Leviathan Axe after throwing it. It was also one of the earliest gameplay/combat prototypes that we tackled.


Despite knowing all the way back in 2015, maybe even 2014, that we wanted to do this mechanic, we were still putting the finishing touches on it months ago. It really did take several years of tweaking and noodling and messing with it. Special thanks to George Mawle for dealing with a ridiculous amount of obscure and difficult code requests and features for the Axe recall alone!

The basic functionality is super simple -- once the Axe is either in flight, stuck in an enemy, or stuck in the world, you can push triangle to call it back.

Its original purpose was really just functional. We were certain we needed a ranged attack, and before we attempted having the Axe fire some kind of projectile, we wanted to see if we could just throw the the weapon itself. Hitting an enemy with a solid / large object is just more satisfying than using a projectile/particle effect.

We realized pretty quickly that in addition to some strong fantasy fulfillment, the mechanic also came with some additional game play benefits we weren't predicting. One of the first things we realized was that hitting enemies on return was basically mandatory. It wasn't only what you would intuitively expect, it was something that was both satisfying to do on purpose and have happen accidentally.


The first of many little helper features that we added was to tweak the return path so that it would specifically move through enemies in order to ensure that it hits them. We used a pretty tight angle to define when the Axe should do this. (Although there is a special pommel late in the game that opens that auto-seeking behavior to 180 degrees!!)

Animation

The animation for the recall actually went through several versions. The first version actually required the player to be static while it returned. And, the animation was more in line with the old god of war in that we went for a bombastic, high profile (hand in the air), facing completely forward approach.

After we moved on to an additive animation that would allow the freedom to navigate, block or evade, we reworked the animation aesthetically quite a bit. The first thing we did: make it feel more casual and less stressful by simply lowering his arm. The second thing we did was rotate Kratos towards the camera, in order to play into the camera a bit more so you could see more of his chest /upper body and not just his back. We also really emphasized both the initial recall moment and the catch moment with a few specifically placed frames and 0 tween time.We wanted the beginning of the recall to feel weighty, almost like a mini-attack, something forceful. For the catch, we wanted to make sure that it feels strong, but we were very careful not to make it feel like Kratos can't handle the Axe or that it's too heavy for him. We had to strike a very specific balance so that the catch feels casual, like he does it all the time, but still carry some momentum through so you can feel the Axe's speed.

Return Time

A lot of time was also spent tweaking the arc and timing of the Axe flying back. Originally we simply set an acceleration/max speed value and returned the Axe in a straight line to his hand. This was problematic for a couple of reasons:
  • The further away you were from the Axe, the longer it would take to get back to you. This was extremely frustrating in combat.
  • It traveling in a straight line often meant you didn't see it.
And, to be honest, the linear path just didn't look very good. After much noodling with George, we settled on a nice curve from the initial recall location to the hand. This increased the chance you would see the Axe return, as well as just looked nicer. There were also quite a few tricks done so that the Axe spins cleanly on the way in. Only in the last second before it goes into Kratos's hand does it rotate itself around correctly. Attempting to rotate the Axe in flight made it look too messy/out of control.

For the speed issue, we eventually came up with the idea to use a hard time-out in addition to a base speed/acceleration. The idea was to make sure that if the Axe was close to you, it came back a little bit faster but was still visible. But, if that distance/speed was going to take more than 1.5 seconds, we would simply increase the speed to whatever was necessary. This allowed us to easily control the max possible time that the player would be spent waiting for the Axe. 


Axe Wiggle

One of the more subtle little mechanics (that was notorious for breaking numerous times during development) is a wiggle the Axe does before it rips itself out of an enemy or wall. We wanted the Axe to feel like it was really wedged into the surface. In order to do that we created a programmatic wiggle that happens for the first 0.1 seconds before beginning its return flight. It used to be much longer, but we started getting complaints that the Axe felt like it was taking too long to come back. And strangely enough, it actually didn't matter if we sped up the return to compensate because it was the added delay before moving that made it feel longer. Some even had the perception that their inputs were delayed.


Polish & Presentation

On top of the movement and animation for the recall, we added a few little things to really polish it off. For sound, we attached the emitter to the Axe itself so that you can actually hear it come closer. The sound itself is also actually tied in with the rotation speed of the Axe. And there are actually 3 separate rumbles used  on the recall -- one for the initial triggering, one for the flight, and one for the catch. (Side note: I was actually thinking of doing a blog post solely on rumbles, since I can be pretty obsessive about them!) Lastly, a little camera shake always helps things feel strong.

Despite how much work it took, this mechanic might be the one I'm most proud of in the game. Of course we took some inspiration from a certain Marvel character... but from a game play standpoint I feel like it really did open a lot of doors we weren't expecting.

Comments

  1. Extremely interesting! I love to be able to read more in-depth articles about the nitty gritty of combat design. Keep it coming!

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  2. Wow! All that, and you didn't even mention button configuration. That could probably be its own blog post entirely.

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  3. This was a fantastic read. My favourite mechanic in the game is the axe coming back to you at your command. Amazing job! Would love to read more.

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  4. Good read. And I think the 'boomerang' axe is the most satisfying part of combat, especially the bouncing it off an enemy's head, recalling it, and then lodging it in them. Great work!

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  5. I have been working in combat cameras for the last month, I would love to hear something about that since what you did is definitely next level even from great action games like Nier Automata. Things like targeting, hinting, zoom, etc etc would make for a great read!

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  6. I agree that it looks amazing, but to be honest I find that the actual controls for throwing and retrieving are over-designed. It should be one verb to throw it (push left trigger) and the same verb to retrieve it (push left trigger) rather than left trigger, right bumper, triangle. The complication of the designed controls makes me de-prioritize using it, which is a shame given its visual coolness.

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    1. Although - that simplifies out light/heavy throws, which turn out to behave increasingly differently as the skill tree expands. Sometimes I find it fiddly; and then others, I like the subtlety or range it offers. Combat feels like a somewhat expressive space in GoW, and so I imagine largely players will perhaps use it more/less dependent on personally preference. Mixing heavy ranged use up with hand-to-hand seamlessly is definitely slightly more advanced finger-spaghetti - but the flipside is it offers a wider range of things it can do, and leads to more visually striking (as well as flowing) combat. I think your suggestion works well if you simplify out what the axe can do - reduce it to light only, ranged hits + a single skill tree, for sure. (As I type I recall - one alternative is, for instance, the Rocksteady-Batman set up of 'quick tap for immediate [batarang] throw, but hold for aiming/expressive use' - the best of both worlds, although tapping a shoulder trigger can be a bit fiddly.)

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    2. It seems like it is important for the player to press Left trigger first as it allows them to strafe and accurately aim their throw, without it, wouldnt the player be always forced to throw the axe in one direction and height? this is a very different mechanic. As for the addition of the triangle button to recall, rather than hitting right trigger a second time, allows the player to not be helpless when their axe has left them. They can continue to punch enemies with their right trigger. otherwise there might be an unsatisfying result of the player never wanting to release their axe, in fear it would leave them vulnerable during the time it would take for it to return.

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  7. See, I love articles like this. I'm not a programmer of any kind, but I'm acutely aware of how it "feels" to play a game. Maybe it's because I have synesthesia, maybe it's because my brain just pays attention to audio-visual feedback way more than other things, but animations and timings and hit-stun and everything like that are so interesting to me.

    The axe recall in God of War looks and feels great, and after just an hour playing, I was thinking it must have taken so much time and effort to get it right.

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  8. RUMBLE! Yes, as you noted in the final thoughts on this article, rumble would make for a great deep dive just like this one. Like camera shake, rumble is a feature that if done right is not noticed at all. I would love to hear about the thoughts and intentions that went into making it.

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  9. Vince PLEASE keep making posts like these. You say there is a chance that these are no interest to anyone and while the field may be narrow, those of us that like it REALLY REALLY LIKE IT. I wish more developers did this. Thank you.

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  10. (Slight puzzle spoiler warning) The return path was a fantastic choice. I loved it even more the first time I realised it is has been worked into some of the puzzles as well!

    On friday I threw the axe (accidentally) into some trees and on the return I noticed the way it would disturb the air so the branches would move even without being hit. Spent 5 minutes playing with that!

    Also the solid feel of the return is always satisfying!

    Another great touch is recalling it from several rooms away - hearing the clattering as it makes it way back to you!

    Thanks for a fantastic game and thanks for this fascinating insight into the design!

    Shrui

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  11. Great article, Vince. I am still curious about how did you guys manage the axe from not hitting Atreus on any circumstantial scenario while returning? Does the code checks for ally collisions and adjusts the return angle?

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  12. No joke! As a dev this was the first question that popped into my head, "Huh neat, wonder how they did the Axe return mechanic."

    Awesome post, it's amazing all the little details that go into something like this. Sometimes I feel like a crazy person spending so much time tweaking things that seem so small but in this case it absolutely paid off. Well done!

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  13. This God Of War may be my favorite single player game, ever. I worked on the Mass Effect Trilogy, and I am still fairly confident I have stronger feelings towards this God of War than I do for the game I helped bring into being.

    Exceptional work, you all should be very proud.

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  14. Recalling the axe is so satisfying in this game. Sometimes I just throw it around at crates and buckets because it's fun to do. As a fan, this game really shines in my heart because of all dedication you guys put into.

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  15. Amazing read. Congrats on delivering perhaps the most engaging set of combat mechanics of all time atm and I hope this blog will continue to grow

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  16. Thanks for this - really great read ! Please do post more !

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