Original Link (now dead) - http://acdm.turbinegames.com/featuredarticles/?action=view&article_id=236


Developer Diary: Creature Rebalance Take Two


By Orion

It has been a few months since we rebalanced monsters and, as promised, we have been keeping an eye on posts and in-game discussion, and playing characters to get a feel for how the changes are working. We are still pleased with the overall changes, but we have also found that some of the side effects of our changes are a little harsher than we had originally intended.

Since the rebalancing, we've seen a lot of discussion about characters - in particular archers - who are having a tough time hitting creatures that they shouldn't be having any trouble hitting. Was something wrong with our data? I combed the files, checked, double-checked and triple-checked the calculations; everything looked good on paper. But as we have seen before, sometimes calculations on paper do not necessarily translate well into reality. So we went into the code and started working through the calculations the same way that the combat system would.

And we found the problem.

See, when a player attacks a creature (or for that matter when a player attacks another player or a creature attacks a player), the target of the attack applies certain modifiers to their defense skill based on things like: How encumbered are they? Are they exhausted? Are they attacking their attacker (or someone else)? What height are they attacking at, and how does that compare to the height of the incoming blow? In the rebalancing, we made some assumptions about the maximum combined effect of all these modifiers - and we assumed wrong.

In particular, we underestimated the effect of the height of the attack. On a higher-level creature, there could be more than a 300 point difference between the effective defense skill at the 'right' attack height and the effective defense skill at the 'wrong' attack height. In other words, a creature with a melee defense of 400 could, in the right circumstances, act like it had a melee defense approaching 600. This made some things a good bit harder to hit than we had intended.

So we considered our options. On one hand, we could go through all the creatures in the game and adjust their melee defense and missile defense skills downward to accommodate the modifiers - effectively rebalancing them all over again. On the other hand, we could instead adjust the defense modifiers themselves downward by changing the code in the combat system. Each option had its own advantages and disadvantages.

Option 1: Change the Monster Stats
With the new tools available to us - tools we built for the initial rebalancing - adjusting the defense skills for all monsters would be much easier than it had been before. The main issue that worried us, however, was touching every creature in the game. An update that vast is bound to have problems. In addition, there was a decent amount of work to be done to figure out how to adjust all the skills. Since the modifiers are all multiplicative, they have a much greater effect at high levels than at low levels, so each monster would have to be adjusted individually. And at high levels, the wide variance of defense skills would still exist -creature skills would still vary over 300 skill points from best-case to worst-case situations. We could make it possible to hit the creatures in the worst-case scenarios, but that would leave them too easy to hit in the best case. Rebalancing against a disparity that large is extremely difficult if we want to maintain any semblance of "average attacks".

Option 2: Change the Modifiers
The modifiers themselves are defined in code, but they are just numbers and can be very easily tweaked. Adjusting the modifiers also gave us the ability to fix an underlying problem - we could narrow the range of the modifiers and thus lower the variance in defense skills between the best- and worst-case situations. In other words, getting to where you can start to hit a particular creature isn't any easier, but once you can hit it, you will hit it more reliably.

Of course, reducing these modifiers changes everything - all missile and melee combat in the game. The changes would reduce defense bonuses for players as well as for creatures, if they were attacking at the same height, so while players would hit creatures more often, players would have a greater chance to be struck by both missile and melee combat from creatures. So in some ways this change was even more sweeping than changing the stats for all the creatures.

Option 3: A little bit of this and a little bit of that.
What if we did both? We could rebalance creature skills for missile and melee attacks, and change the defensive modifiers. This seemed like a viable option until we realized that it includes the drawbacks of both option 1 and option 2, and doesn't give us anything in exchange. The potential for creating more imbalances instead of fewer was just too high.

Resolution
In the end we opted to go with Option 2, adjust the modifiers themselves, and leave monster stats alone. This allowed us to tighten the effective range of defensive skills in combat, to keep the variance between best- and worst-case scenarios manageable even at high levels. This also makes further tweaks less difficult, should the need arise. It does mean that creatures will hit players more reliably than they did before, but players are actually quite good at absorbing damage - much better than creatures.

Next, we needed to test the changes.

Testing
Srand took the melee cause to the battlefield. She loaded up a mid-level sword character and sought out Olthoi Swarm Soldiers. Only a day before, these creatures had evaded her mercilessly. Now, however, she reported hitting more often - often enough, in fact, to kill the little buggers. Perhaps most heartening to know was that she did not use buffs beyond what her level could normally access, and that her attributes and skills were only adequate, not especially high, for her level. Heck, srand was actually fighting above her skill level and she was doing quite well.

After some more testing with different levels of melee characters, srand gave me the thumbs up. She had signed off on the melee end of the changes and handed the remainder of the testing to me.

I grabbed my archer from the previous day's testing and got him to the mid 80's. This is a good testing level. You've just entered the really high areas for the first time and when you fight above your skill level, you really know you are fighting above your skill. We expect most characters of this level to have access to level 6 spells, so I buffed with 6's and dove into a fight with Olthoi Swarm Mutilators. They are above my skill level, but we needed to get the feel of a tough fight.

I was wearing average quest equipment: sunstone gauntlets imbued with the bow amulet, new Greater Shadow Amuli (Scored and Hardened), and underneath I threw on Asheron's Greater Coordination Raiment. My bow was not imbued, but was twinked to 150% +15%. I used Deadly Piercing arrows. All in all I was less than optimal but adequately average.

The day before, fighting a foe that was on the edge of where I might be able to solo was difficult, very difficult. Today, with the changes to code in place I was hitting my target more consistently. But wait, this creature is actually outside my skill level range. They have more defensive skill than I should really be able to touch, and they are designed against more than one player of my level. This is suddenly good, very good.

The next test, the dreaded Tiatus Raider, is right around where my skill level resides. I shoot from far away and hit. I hit again, then again and on the fourth shot I hit the landscape. He falls before he gets to me. I decide that this is not a fair test. I need to be in melee with him.

Spawning another, I run up to him, and then around him, which puts him in melee so I can test accurately at close range. First shot misses, 2nd through 5th hit. I miss once more and he drops on the 7th arrow. I rinse and repeat this scenario a few times to get the feel and find that I am about hitting him about 55-75% with my accuracy bar at +35%. My buffed skill is up around 375, including the two moderates. This feels better to me.

Conclusion
For the past few months I've been saying, "Just alter your attack height." I meant it, and still do. But now the bonuses that are applied to the defender are not as imposing as they had been. This creates a tighter skill curve at the high end of the spectrum. Where once a creature was able to gain a 160 point bonus to their skill or higher, now they can only achieve an 80 point bonus. We tweaked the code that governed the defensive bonus to make it more reasonable. Barring any changes, this code will go into the game in the August event.

The characters most impacted by this change will be archers, who can once again make adjustments to their accuracy bar and expect to hit their targets. This is not going to make it possible for an archer to fire on the lowest setting against creatures around their level, nor is it going to guarantee that setting your accuracy bar to 50% will hit consistently. What this change will do is tighten the creature's defensive variance enough to produce a noticeable change to missile combat.

As a pleasing side note, melee players will also see a noticeable change. Melee players will receive the same benefit as archers with this change. Melees may notice the change more as it is an alteration to a system that melee players have been dealing with since the beginning of the game.

Mages, there is not much for you with this change. This system had no bearing on the difficulty for landing spells on creature and so you will remain unaffected.

In all, these changes may not be the last step, but they do offer a positive change to the feel of hunting. These changes will be monitored, of course, and altered as needed in the future.

Good luck and happy hunting!