Game Design/Balance trap: for cost evaluation
Posted: 29 Dec 2010, 02:18
I was reading over a couple different pieces on game design written by other forum members here recently, I tended to come across this concept alot, balance should be based on "for cost" evaluation.
Thinking about this idea a fair bit, I'm pretty convinced that for cost evaluation is at best an occasionally useful tool, at worst it's a horrendous trap that causes you to overlook more powerful cues in favor of an arbitrary and abstract mathematical calculation.
"For cost" is deceptive, and here is why: If I have a fast melee unit, and a slow ranged unit, and in a 1v1 scenario the melee unit kills the ranged unit, that will not hold true necessarily for 2v2, 3v3 16v16, whatever. Even the slightest variation in range and movement speed will result in a widely variable cost vs cost result. There is no one cost vs cost test that will produce an accurate depiction of every cost vs cost scenario. A krogoth will kill infinity peewees in 1v1 battles, and die to maby 30 if perfectly surrounded and microed against, and that's not just an issue of micro or ideal battle placement, it's an issue of unit role. more on that later though...
Additional to "for cost" being deceptive, it's unrealistic. It's a bit simplified in TA with the 1 resource (sorta) system, but in other RTS games like starcraft2 we see this phenomena more clearly. How much minerals is gas worth? Well, in the early game gas isn't worth very much, it allows you to get out a few key tech structures and units, but focusing too much attention on gas will decrease the immediate DPS and hitpoint values of your army. There are many strong rush builds that rely on getting late gas because if you have an early game mineral heavy army your army is basically just bigger, stronger, tougher than whatever the opponent will have in the early game. In starcraft, gas gets you upgrades and lategame tech, so in the late game more and more it becomes extremely valuable. So... back to the original question, how many minerals is a single unit of gas worth? The answer is that it fully depends on what stage of the game you are in. For cost is unrealistic because the actual cost of a unit shifts throughout the game in a normal RTS, even if the # in resource cost remains the same. There are many more resources than just the in game mineral count, and those resources become more and less valuable as the game goes on.
Adding onto that, for cost is unrealistic because it doesn't account for hidden costs. If I am examining a T3 unit, in TA, there are many many many hidden costs we do not see. How much did it cost to get the factory running in the first place? How much did it cost to survive up to that point? How much cost in variation from the build I was attempting was there? In certain TA variations that used to be played, you could not switch easily between vehical and kbot tech from one teir to the next, it was an early game choice; so certain unit combinations had immense in game cost because they required 2 extremely expensive factories and tech paths, however, their actual unit costs were minimal. In a 1v1 game those combinations would be ridiculously unrealistic, but in a 2v2 game the balance may have been totally different. Hidden cost is virtually impossible to algorithmitize, at least not in one sitting. The hidden cost for one unit may not even be the same as the hidden cost for another unit in the same tech tree built by the same structure: in starcraft 2, if I am relying on a sentry heavy army I have spent alot of gas, and thus the hidden cost of trying to buy colossus is huge, because they are costing me large amounts of my most valued resource; it may be more realistic to build immortals, they cost less gas and let my army be stronger in the unit it is relying on. These structures certainly exist and are valid in all other RTS games as well. Hidden cost can even be built into a unit dependant on what the opponent does. Cost vs Cost is EXTREMELY inadequate at evaluating real game scenarios.
In truth, for cost testing is woefully incomplete as a balancing tool, virtually every for cost test would not produce liniar graphs if unit counts are scaled, small numbers of zerglings will defeat small numbers of marines, but die horrendously to large numbers. This doesn't even account for the myriad of game situations where scenario plays more into effect than raw cost vs cost unit count, marines are better with a wide arch, so they are reliant on terrain, and any unit that controls terrain (infestors, tanks, colossus) will be powerful against them, but this is virtually impossible to accurately test in cost vs cost simulation, let alone more complicated (and therefore more realistic) situations. Many units have high worth without acctually even doing any damage. Flash tanks in OTA were fast and could rip apart your economy, they gave their owner map control, so he could expand freely and you would have to constantly defend, they were more valuable than their outright cost. In starcraft cloak does this for many units. Dark Templars are useless if they are seen, but the simple fact that they have to be seen means that a player cannot move out against them until his tech tree has reached a point where he is comfortable in the amount of detection he has.
Basically, I'm arguing here that cost vs cost testing has very little authority into the balance of units against each other and relative to the game. I think it should be implicately understood by game designers of all spring projects that cost for cost testing is fine if you take it for what it is, but what it is not is a good gauge of the way things should be viewed. I've heard a fair few people purporting this tool in various places, and I'm not going so far as to say that it doesn't have it's uses, but I want to strongly encourage spring game designers not to overvalue cost vs cost test results. Most units should not be very close to each other in most cost vs cost tests, balance comes from the realisticness of getting a certain sized army of a certain type of unit in a real game scenario, the hidden cost of moving that army around the map (slow units cost more to be away from the base than fast units and soforth) and the many many hidden costs associated by terrain and positional advantages and disadvantages. There are just so many hidden costs and considerations that in one cost vs cost test you can't ever really claim to have learned anything substantial. Ultimately, over and over again, unit role breaks for cost testing and makes it useless.
So where to go from here? I'm not really sure, get into games and play the hell out of them I guess? Find replays from other players and go over them with a fine tooth comb to look for things you weren't expecting relative to your design? I think unit statistics are somewhat telling, who does damage to what in real games played? I think ultimately balance is a bit subjective to begin with, I kinda feel like it's best to tweak away from everything being useful and instead aim to tweak things such that the current state of things is fun. It's probably not fun to face the same strategy over and over again in a game, but it may be less fun if there are 4 alternates that are barely different. If one unit is crushing its counters due to real game situations, buff counters maby? nerf unit? depending on what other interactions you expect to encounter. Balance is not an easy task, but I'm convinced that cost vs cost testing isn't even close to the ultimate answer.
Thinking about this idea a fair bit, I'm pretty convinced that for cost evaluation is at best an occasionally useful tool, at worst it's a horrendous trap that causes you to overlook more powerful cues in favor of an arbitrary and abstract mathematical calculation.
"For cost" is deceptive, and here is why: If I have a fast melee unit, and a slow ranged unit, and in a 1v1 scenario the melee unit kills the ranged unit, that will not hold true necessarily for 2v2, 3v3 16v16, whatever. Even the slightest variation in range and movement speed will result in a widely variable cost vs cost result. There is no one cost vs cost test that will produce an accurate depiction of every cost vs cost scenario. A krogoth will kill infinity peewees in 1v1 battles, and die to maby 30 if perfectly surrounded and microed against, and that's not just an issue of micro or ideal battle placement, it's an issue of unit role. more on that later though...
Additional to "for cost" being deceptive, it's unrealistic. It's a bit simplified in TA with the 1 resource (sorta) system, but in other RTS games like starcraft2 we see this phenomena more clearly. How much minerals is gas worth? Well, in the early game gas isn't worth very much, it allows you to get out a few key tech structures and units, but focusing too much attention on gas will decrease the immediate DPS and hitpoint values of your army. There are many strong rush builds that rely on getting late gas because if you have an early game mineral heavy army your army is basically just bigger, stronger, tougher than whatever the opponent will have in the early game. In starcraft, gas gets you upgrades and lategame tech, so in the late game more and more it becomes extremely valuable. So... back to the original question, how many minerals is a single unit of gas worth? The answer is that it fully depends on what stage of the game you are in. For cost is unrealistic because the actual cost of a unit shifts throughout the game in a normal RTS, even if the # in resource cost remains the same. There are many more resources than just the in game mineral count, and those resources become more and less valuable as the game goes on.
Adding onto that, for cost is unrealistic because it doesn't account for hidden costs. If I am examining a T3 unit, in TA, there are many many many hidden costs we do not see. How much did it cost to get the factory running in the first place? How much did it cost to survive up to that point? How much cost in variation from the build I was attempting was there? In certain TA variations that used to be played, you could not switch easily between vehical and kbot tech from one teir to the next, it was an early game choice; so certain unit combinations had immense in game cost because they required 2 extremely expensive factories and tech paths, however, their actual unit costs were minimal. In a 1v1 game those combinations would be ridiculously unrealistic, but in a 2v2 game the balance may have been totally different. Hidden cost is virtually impossible to algorithmitize, at least not in one sitting. The hidden cost for one unit may not even be the same as the hidden cost for another unit in the same tech tree built by the same structure: in starcraft 2, if I am relying on a sentry heavy army I have spent alot of gas, and thus the hidden cost of trying to buy colossus is huge, because they are costing me large amounts of my most valued resource; it may be more realistic to build immortals, they cost less gas and let my army be stronger in the unit it is relying on. These structures certainly exist and are valid in all other RTS games as well. Hidden cost can even be built into a unit dependant on what the opponent does. Cost vs Cost is EXTREMELY inadequate at evaluating real game scenarios.
In truth, for cost testing is woefully incomplete as a balancing tool, virtually every for cost test would not produce liniar graphs if unit counts are scaled, small numbers of zerglings will defeat small numbers of marines, but die horrendously to large numbers. This doesn't even account for the myriad of game situations where scenario plays more into effect than raw cost vs cost unit count, marines are better with a wide arch, so they are reliant on terrain, and any unit that controls terrain (infestors, tanks, colossus) will be powerful against them, but this is virtually impossible to accurately test in cost vs cost simulation, let alone more complicated (and therefore more realistic) situations. Many units have high worth without acctually even doing any damage. Flash tanks in OTA were fast and could rip apart your economy, they gave their owner map control, so he could expand freely and you would have to constantly defend, they were more valuable than their outright cost. In starcraft cloak does this for many units. Dark Templars are useless if they are seen, but the simple fact that they have to be seen means that a player cannot move out against them until his tech tree has reached a point where he is comfortable in the amount of detection he has.
Basically, I'm arguing here that cost vs cost testing has very little authority into the balance of units against each other and relative to the game. I think it should be implicately understood by game designers of all spring projects that cost for cost testing is fine if you take it for what it is, but what it is not is a good gauge of the way things should be viewed. I've heard a fair few people purporting this tool in various places, and I'm not going so far as to say that it doesn't have it's uses, but I want to strongly encourage spring game designers not to overvalue cost vs cost test results. Most units should not be very close to each other in most cost vs cost tests, balance comes from the realisticness of getting a certain sized army of a certain type of unit in a real game scenario, the hidden cost of moving that army around the map (slow units cost more to be away from the base than fast units and soforth) and the many many hidden costs associated by terrain and positional advantages and disadvantages. There are just so many hidden costs and considerations that in one cost vs cost test you can't ever really claim to have learned anything substantial. Ultimately, over and over again, unit role breaks for cost testing and makes it useless.
So where to go from here? I'm not really sure, get into games and play the hell out of them I guess? Find replays from other players and go over them with a fine tooth comb to look for things you weren't expecting relative to your design? I think unit statistics are somewhat telling, who does damage to what in real games played? I think ultimately balance is a bit subjective to begin with, I kinda feel like it's best to tweak away from everything being useful and instead aim to tweak things such that the current state of things is fun. It's probably not fun to face the same strategy over and over again in a game, but it may be less fun if there are 4 alternates that are barely different. If one unit is crushing its counters due to real game situations, buff counters maby? nerf unit? depending on what other interactions you expect to encounter. Balance is not an easy task, but I'm convinced that cost vs cost testing isn't even close to the ultimate answer.