Designing Difficulty Options In Games

Gamasutra is running a story about how the "hard" modes in games can be designed to include difficulty, but not frustration. They give some examples of the changes made to several games as their difficulty settings are increased, and they discuss some of the simple options, such as increasing the number of required button presses, or increasing the relevant numbers by an arbitrary amount (a boss on easy may hit you for 10 damage, whereas a boss on hard may act the same but hit you for 100 damage). They also talk about maintaining the "illusion of fairness." Quoting: "Bungie's Halo series is often praised for its excellent execution of difficult play in the form of its Legendary mode. Not surprisingly, the team took a very well-thought out approach to introducing and tuning difficult play. Halo 3 gameplay designer Francois Boucher-Genesse explains that it's not just a case of one formula fits all. 'It's not like we just cranked every enemy's health by 200% and called it Legendary,' he said. 'There was a good amount of custom changes made per mission as well. In that sense we encourage players with previous Halo experience to play at least on Heroic, since they get to see the game in its full scale.'"

Comments

Maybe about the curve?

[nine-times]

My biggest gripe with game difficulty that comes to mind is when I feel like it's making the whole thing hard for the sake of being hard. Guitar Hero 3 comes to mind. It's like they're assuming you've played the other Guitar Hero games, were good at them, and only bought the new one because you wanted a bigger challenge. Some of the Tony Hawk games have the same problem, so it's probably those developers.

I can understand wanting a challenge, so I don't think there's anything wrong with it. But the problem manifests itself by having the difficulty curve all wonky. You can be very good at Easy, and still not be able to complete relatively simple songs on Medium. Same with Medium->Hard, and Hard->Expert. Rock Band, on the other hand, can also be pretty challenging, but the curve is more gradual, so IMO it works better. It's clear the developers were focused more on having the game be fun for all levels of expertise, rather than making a good challenge that only hardcore fans will appreciate.

I think this applies for pretty much all games, across genres. Guitar Hero was just what came to mind. Ideally anyone should be able to play, but it should be more *fun* to play harder difficulties if your better at the game.

Re:Maybe about the curve?

[geminidomino]

There is a practice mode to help you learn the fingering and sequences. perhaps you need to actually do some "Practice", or do you just expect that you can rock out on a harder mode because you are perfect at a simple mode?

That would be the wonky learning curve being referred to, yes. If you can get 99-100% on Freebird, Misirilou, and Psychobilly Freakout on Medium, but can't even beat "Mother" on Hard, what you have is a gap where the game rejects "difficulty" for "frustration", and if you're not "hardcore", you just don't want to play anymore.

You gotta have a carrot.

Re:Maybe about the curve?

[jonaskoelker]

It's like they're assuming you've played the other Guitar Hero games, were good at them, and only bought the new one because you wanted a bigger challenge.

I fail to recognize this. Let me first admit, though, that I have played other GH games very little. Three Aerosmith songs in my local EB, one or two songs from GH2 on easy, tier 1. My experience with GH3 is also incomplete: I've 5-starred easy (and, IIRC, medium), and completed ~10 songs on hard. A handful of FCs on easy too.

My experience is that the difficulty rises slowly within each difficulty level, with a few harder-than-normal boss fights in the mix, and then jerks upward when you go to the next difficulty level; the jerk is enough that you note it's significantly more difficult, but not enough to be impossible.

It'll be fun to see whether the difficulty increase between tiers is more pronounced on hard and expert.

making a good challenge that only hardcore fans will appreciate.

I would say that GH3 spans a large interval of difficulty level. Thus it should be relatively simple to reach a challenge level that matches your skill. Also, there are several goals you can set for yourself that you can work towards in a non-linear fashion (the bonus songs are great for this); for instance, n-starring all songs, FCing all the songs you had heard before playing the game, FCing all songs. Now vary the difficulty level and your settings for performance mode, precision mode and hyperspeed.

Sure, FCing TTFAF with precision mode and hypespeed five (or performance mode) is INfuckingSANE. And that's great--it means you won't run out of challenges soon. The greatness of this is of course depends on the fact that there are plenty of easier challenges with a wide selection of difficulty level you can work at, and lots of meaningful goals you can achieve during your play to keep the experience rewarding.

So, in summary: the hardest parts of GH3 are hard enough that maybe, maybe, one person will complete them. But if you go there, you're asking for it. A sense of accomplishment is accessible to everyone, and there are challenges of sufficiently varying difficulty that your sense of accomplishment can match your level of skill.

Spilt cpu intelligent and cpu handy cap / cheating

[Joe The Dragon]

Spilt cpu intelligent and cpu handy cap / cheating in to there own settings. Do not put them under the same setting. Heroes of might and magic 1 had that.

Using metrics from gameplay to tweak difficulty

[drexlor]

I wrote a paper in college about how video games could evaluate and adjust difficulty based on metrics while the gamer is playing. I think a game's difficulty that is based off input from the controller and game statistics would help people have a more enjoyable gaming experience.

If the game can receive input from the gamepad/joystick they can measure heat, motion, button hitting frequencies, and things of that nature.

Software inputs can be used too. Time measured in zones, level completion times, and time to defeat creatures can be measured to add as heuristics. Death counts and locations can be used to determine what areas need work.

These inputs have been associated with stress levels in gaming and can be used to adjust creature abilities, time limits, weapon power, and directional support for the gamer. If the gamer is playing well the difficulty will become more difficult over time and if the player is having trouble then the difficulty can be toned down slowly and selectively. Directional help can also be used if the game thinks the gamer is lost.

These could help create a more dynamic game that fits to the gamer.

Re:Using metrics from gameplay to tweak difficulty

[Mprx]

Dynamic difficulty is a very bad idea. There's no sense of accomplishment if the game punishes you for doing well. The only way it can work is if manipulating the difficulty system is intended as part of the game, as in Battle Garrega where the only way to succeed is learning how to keep the dynamic difficulty low, which is a difficult sub-game in itself.

FPS AI

[PaganRitual]

Has there ever been a first person shooter for where the difficulty level isn't simply an indication of how close you want your enemies to aimbots?

I can easily think of the negative extremes, such as Soldier of Fortune 2, with the infamous jungle level, and my own personal experiences with being shot through thick jungle, repeatedly having grenades land perfectly at my feet from enemies that haven't even seen me yet, and training a sniper scope onto the back of an enemies head at maximum range, only to have him suddenly turn around and go sneaking towards me. And Call of Duty, where increased difficulty was just the games way of asking exactly what percentage of the entire opposition army you wanted to face at once.

I appreciate that Halo tends to take a beating every time it's put forward as a paragon of game design and gaming in general and that the Halo fanboys with mod points will destroy me, but seriously, one of the gripes is with the claim that Halo's AI is somehow fitting of the Legendary title on it's hardest difficulty, when anyone playing the game sans rose-colored glasses has trouble not noticing that the enemies now simply fire faster, harder and lead perfectly.

"It's not like we just cranked every enemy's health by 200% and called it Legendary," he said. "There was a good amount of custom changes made per mission as well ...[snip]... What did make a difference was the time spent tweaking and fixing issues to make the game fun on every difficulty level. All titles had more bad guys, stronger and more accurate enemies with faster projectiles. And they used similar numbers for each of these parameters."

So in other words they made the enemies fire faster, harder and lead better. Thanks for clearing that up.

On the plus side, Far Cry's AI was reasonable, but had noticable holes, such as when it somehow thought it was hidden yet you could clearly see it sneaking towards you down an open dirt track, seemingly with an "If I can't see him then he can't see me" attitude. And if I remember correctly it improved further in Crysis. Although the thing that seems to happen with games like that is as soon as you claim that the AI is brilliant any single example of the AI not working flawlessly has people uploading videos to youtube showing that the AI is completely garbage because of this one time it got stuck on that shark outside the hut or something.

Are there any really decent examples of FPS AI or do we have to still be happy with running the Reaper Bot in Quake?

Re:Civ IV

[ShakaUVM]

That's an interesting question. I actually sketched out a fairly detailed document on how I'd write a Civ AI and downloaded the API for it, but couldn't make enough sense of the code to start hacking on it. I do have a background in writing game AI - I wrote a bot for Quake, and have modded quite a few games (see my URL for the biggest one), but I couldn't get to the point where I grokked the code. I know it's not much of an excuse, I obviously could have spent more time on it, and spent more time digging up docs on it, but there it is.

Essentially, the problems I see with the Civ 4 AI are this (in no particular order):
1) Too easy on noble (and lower). As in, without doing anything particularly interesting, you end up outteching the AI by progressively larger margins, and they don't have much of an army to stop you. At some point, you can just roll in with a small stack of gunpowder units and wipe out all the enemy civs.
2) Surrendering to Switzerland. A number of times I've been beating the snot out of a civ, and offered it vassalage, which it would refuse. I'd beat on it some more, then it would surrender to a random third party that neither of us are at war with.
3) On Monarch and higher, the game makes these obscene superstacks of units for the AI. As in, there'll be 30 or 40 tanks or knights or whatever on one city, and 10 to 20 units on all the other cities. If a human is at the point where it can kill such a stack, he's going to win eventually, but it requires an amazingly tedious amount of time to do so, and the AI appears to be able to pull massive amounts of military units out of its ass, and apparently without paying upkeep. Or if it is paying upkeep, then it's certainly a bug, since it'll get even more out-teched since it can't afford research.
4) The AI's lacking in basic tactics sometimes. It'll suicide entire stacks of 20 units against a trio of fortified machine gunners, won't use terrain intelligently (well, some of the time it will), doesn't use spies to take out critical resources (like a lone copper or horse resource, instead attacking horses in the tank era or a resource that I already have 3 of).
5) It's careless with its workers, allowing them to get captured easily. I know this was patched in the latest version, but the last game I played I captured a lot of enemy workers just tooling around. They're especially trusting before war breaks out.
6) It's general method of moving troops and ships around is just odd sometimes. I've seen enemy units get stuck in a mountain, trying to pathfind across it, or individual units approaching my stack when I'm at war with them.
7) The AI, in general, is completely reactive. If I set my spy rate up higher, the AI will set its spy rate up higher. If I turn up my culture rate, he turns up his culture rate.
8) Too trusting. If I'm at peace with an AI, but building up a large force along the border, it will mostly ignore it until I invade. I'd like to see it take up defensive positions with spare units and build forts in border tiles (especially in chokepoints) instead of being constantly surprised every time someone declares war on them. Likewise, a lot of time they'll declare war without their armies being in position for it.

What I'd like to see is this:
1) High level AI tasks. Have AIs decide perhaps 30 turns in advance that they're going to betray a peace treaty and start cranking out units and positioning them on a border, ready to invade. If relations haven't improved on the target date, rush in with everything. Alternatively, have it decide to make a solid effort to take over the new world, instead of the piecemeal way that it expands to new continents now. The different AI types (techers, expansionists, militarists) would have different likelihoods for the various tasks. Essentially this would make them appear to be more human, and more interesting to work with.
2) Set them up to beeline different techs and wonders to match a specific objective chosen at the beginning of the game. For example, an AI could go with

Re:That's Easy!

[Impy the Impiuos Imp]

I absolutely love setting the highest difficulty as a challenge for games.

One of the most brilliant "hardest" settings was in Thief, where in the hardest setting, you were not allowed to kill anybody. Hence the whole game became a puzzle of sneaking, with no more than blackjacking someone.

Countless times I heard someone talk about how good they got with the sword in Thief, but I always wondered what the point of that was. If I wanted melee action I'd play some other game.

Accomplishments on Hardest, Never Looking Up Solutions Online

• Duke Nukem (2nd hardest setting -- hardest was with respawn, designed for multiplayer action)
• Icewind Dale II on Heart of Fury mode, with 2 true level 1 characters, no imported items.
  Realized this could probably be done with 1 fighter, though I didn't try it. And no, I'm not lying. You didn't think the bards wrote tales about your pathetic adventures, did you?
• Serious Sam on Serious, but certain times ammo would run short and the only option was to rocket jump somewhere mildly safe and slowly pick off people with your magical recharging revolvers or whatever it was.
• Quake, 2 Expansion Packs, Quake II, etc., on Nightmare. This includes finding the Nightmare settings mechanism, done cleverly and in-game.
• Duplicated the 30s Lava God quick run in Quake, but with an embarassingly slow 36 second time.
• All 120 or 125 levels of original Lemmings without looking up any answers. Got interested because a "high-Q" colleague couldn't solve one of the levels. Included hacking it myself to get around the shareware limit on 5 game starts. Ahh, puzzles.
• Both KoToR games. Of course, "hard" is a joke on those games, with the exception of the boss encounters. (Try going to Korriban immediately after training to be a Jedi in the first one, then getting by Calo.) Set a goal of trying to make these encounters as easy as possible while soloing whenever not required by the story to take someone along. Final runthroughs involved manhandling Calo at both encounters as well as utter devastation of all other boss encounters, and taking 18 levels of Jedi (which meant getting to Dantooine by only leveling to level 2, which is required to leave the damaged ship in the beginning.) For KoToR II, I eventually manhandled the undead guy in the Korriban encounter (such that Kreia "saving" you by psychically telling you to flee seemed idiotic) and was able to 2-shot, but not quite 1-shot, the undead guy in the second, endgame encounter, indefinitely. So I could have, in fact, stood there fighting him forever. In theory I could have one-shot him had all the rolls hit superbly, but that never actually happened.
• Starcraft -- Another game where "hard" wasn't really that hard. But I like to point out that Tassadar was an idiot for feeling he had to sacrifice himself. I had the brain well under control, thxbie.
• Total Annihilation -- Meteor level, need I say more. Geeze.

And some (partial) failures

• Kingpin on "Real" mode -- More of a novelty, if you got shot or clubbed, you pretty much died, as you should. Tough to make it past the first guy with a club since you didn't have your gun yet, and the AI, built on hitting you a number of times before you died, getting you very quickly. Never made it past the first level.
• Warcraft III -- Not a failure per se -- I made it 2/3 the way through the second act before quitting out of raw hatred for the way they made it more difficult. For example, your towers couldn't out-shoot the meatwagons, hence you always had to send out a party to intercept them. I only found one spot on one map where I could place a tower at an elevation so high that it outshot a meatwagon, and it felt as if the devs had missed that spot. :( Still, I managed to survive and get all the optional goals up to that point (an additional restriction I put on myself) including the "save the offshoot village way in the north" in the "you're bei

Re:Big problem in strategy games

[Impy the Impiuos Imp]

> Things like this can really piss off a gamer, but thankfully are mostly disappearing from
> today's games, as AI programming has advanced enough to not require the use of such.

Oh, you know what I hate? It's what I call "Sim Ant Syndrome"

In Sim Ant, you simulated an entire ant colony, though you could take charge of any ant you wanted in order to move it somewhere, usually to leave a chemical trail to food or a battle.

So far so good. But the enemy ant colony always made a bee line (so to speak) for whatever ant you had posessed, whether you left a chemical trail or not. If you switched ants, the other ants always immediately switched to attack that new ant -- even before you had done anything with it.

Mech Warrior Mercenaries, the best Mech game I've ever played, also suffered from this. You'd go out with your two wingmen and the opposing triad of mechs would always come after you, end of story.

So I put Sim Ant Syndrome to work for me, and got in the little 160 mph zipper robot, and assigned the Atlas D and Atlas K to my wingmen, and ran all over the place while they slowly chewed up the idiots always gunning for me.

Ahhh, the good old Atlas D. There was a point 2/3 through the game where the mechs you "found" started being seriously upgraded from your already-looted stable of mechs, thus making obsolete all the old mechs -- except the monstrous Atlas D, which was so massive it could still stand up to the new mech pounding, and could loadout enough stuff to fight back more than effectively. And the Atlas K, the new mech's Atlas, sheesh.

Within a few levels of the Atlas K, though, the game got to a point where it would crash when I got to a certain spot and I couldn't get around it, even reverting to a fairly ancient saved game. And that was with the final patch ever released. I wonder if anyone ever finished MWM on "hardest".