Post-Play'em - Observations on Game AI

Posts Tagged ‘Brutal Legend’

Brütal Legend’s RTS elements

Tuesday, February 16th, 2010

Ok… now I get what Tara Teich is going to be talking about in her AI Summit lecture on Brütal Legend. She is going to be focusing on the challenges that they faced when they introduced RTS elements into a brawler-style game. When I did my first look, I hadn’t really seen evidence of how the RTS/brawler cross-over was happening. I just now played the first major battle (after you set up the stage for the first time), and I really see the mechanism at work.

Trying to manage all the different types of “units” you can summon makes for an interesting gameplay element. What’s more, as a player, you have to switch between solo brawling and teaming up with the other units. For example, you can get together with a group of headbangers and form a moving moshpit. At times, however, you have to make the decision to disband the group and go back to mashing solo, or team up with another group. Oh yeah, and you can still just issue general orders to units you aren’t teamed up with — orders like “come to me”, “stay and defend” or “attack that”. This can be done in addition to the local control as a team.
If it is difficult for me to manage what is supposed to be happening in the grand melee of units, I can imagine that trying to organize it properly from an AI standpoint must have been challenging as well. Because the units need to be nearby in order to be ordered or paired up with, I wonder if the units try to stay close to the player?

But what happens if there are legitimate people to kill that I’m not near? I can see frustration developing if the units were to just go off and attack on their own. Sure, it’s the right thing to do from a tactical standpoint, but the whole point is to give the player the sense of command. In a way it combines the autonomy of RTS units with a little bit of companion AI from the likes of Left 4 Dead or Mass Effect.
The other question is if they are doing combined tactics when they are on their own. I don’t mean advanced stuff like flanking, etc. Rather, are they just picking the nearest enemy or are they spreading out for maximum coverage?
On both of these points, I will have to do some more observation of what’s going on — and that usually means watching one of my kids play instead of doing it myself. They usually don’t argue much when I tell them it’s their turn.

Brütal Legend: First Look

Sunday, February 14th, 2010

Next on the pre-GDC flush of my GameFly queue is the metal-themed game, Brütal Legend from Double Fine. This one has a little more urgency in it because my friend and AI Game Programmers Guild colleague, Tara Teich, did a lot of the AI for it. She is going to be explaining some of the challenges she faced in her lecture at the 2010 AI Summit at GDC. Specifically, she is going to be talking about marrying some facets of an RTS game (always a little more difficult on a console) with those of a typical brawler game.

Anyway, from a purely thematic standpoint, I have to find myself laughing rather often. It must have taken quite some time for the design team to make a list of every single hard rock and metal sterotype… or should I say stërëötÿpë… and figure out a way to insert it into the game. Anyway… that’s design, not AI, but it was worth noting. Very amusing game so far.

Anyway, from an AI-focussed view, it is certainly in a different ballpark than some of the other games I have been reviewing on here. RTS games like Company of Heroes, RPGs with heavy AI components such as Fable 2, and animation masterpieces like Assassin’s Creed are on a completely different wavelength than something like Brütal Legend. It’s not meant to be complicated, intense or clever. Instead, it’s meant to be accessible.

Give it Away, Give it Away, Give it Away Now…

One thing that I noticed just before I sat down here at the computer was the “tells” during a “boss battle” with a giant metal spider. As is typical in boss battles, the enemy will have a certain list of attacks that it performs on you. Each one of those attacks is preceded by a short preparatory move so that you know it is coming. There’s not a lot of subtlety or guile in boss battle “tells”. That’s the whole point. The other aspect of having tells is that you can pretty much string together attacks in any random order because the only thing the player is looking for is tell -> attack. On the other hand, I thought I detected a distinct pattern of some of the attacks. For those of you who have fought that spider, it seemed like there was a sequence of
  1. release the little spiders
  2. shoot the splashy stuff
  3. the engine gets exposed
It happened enough times that I could eventually put together the sequence of dodging the splashy stuff, tossing off the little spiders, and then shocking the engine.
To be honest, though, I really don’t like this type of combat. I’m not a puzzle-solving kind of gamer. I’m more of an NP-rediculous, react, plan, solve, be creative with how to ass kick, kind of guy. However, that’s a legit design decision for the majority of the gaming public and I’m cool with that.
All Together…

I can see where Tara is going with her idea of merging RTS and brawler features, though. When you start fighting along with the headbangers (some of whom I swear I went to college with), the game introduces you to a few rudimentary commands such as follow me, stay here, attack that, etc. Those aren’t so intriguing from an AI standpoint. A little further on, however, you are introduced to the idea of the “mosh pit” – another wonderful twist on a metal cliché. When you are surrounded by 6 of the headbangers and they form the moving circle around you, it is amusing. When you actually enter combat with this ring of cranium-wielding warriors, it becomes interesting.
I wish I had video of these battles so I could slow it down. I want to see how much intelligence is going on with their respective target selection. It seems like they are doing more than just hitting anything that comes near them. They do go out and find a near-by target, I think. However, do they divvy those targets up or is there occasionally some inefficient overlap where 2 ‘bangers go after the same guy? Dunno… This would have to be done with some sort of sorting and semaphore system — in layman’s terms, each one saying “I got this guy here… find your own”. I simply don’t know if that would be worth going through the trouble, however.

The animation during the cutscenes is nice. The faces (especially Jack/Eddy) are expressive in an amusing way. I have to assume that is hand-done, however. Not much of an AI-fest there.
The rest of the animation is rather typical. Again, they aren’t trying to be Assassin’s Creed here. I’m OK with that.
I think what I’m looking forward to most as I move through the game is more of the group scenes. I want to see how the groups of headbangers (or whomever) deal with larger groups of the enemies. After all, that’s what Tara identified as a challenge of sorts.
In the mean time, I’m just gonna rock out!