Monday, August 24, 2009

Lotro: Cracked Earth

Oatbarton and it neighbouring Goblin camp was certainly a growing up experience for my level 29 Loremaster. While struggling to solo these difficult quests I learned that LM's are not invincible. I also learned quite a bit more about how to use my skills especially one sublime skill called "Cracked Earth". Cracked Earth is not only a very useful multiple target root, it is also one of the most cleverly designed skills I have ever come across in an mmo.

In the first instance Cracked Earth is a ranged spell that roots up to five targets within a 7m area. While rooted they cannot move although they can attack you if you get too close. Very useful against those groups of melee mobs that can make life so difficult for a lone Loremaster.

Now for the first clever bit: It is not an instant root. It takes ten seconds for the root to stick. When I first got the skill and tried it out I was very disappointed. Ten seconds is lots of time for angry mobs to run up to you and start whacking. Of course the answer is that you have to run away from the mobs for this first ten seconds until the root holds. Making sure you have somewhere to run that won't aggro a bunch of other mobs is part of the careful preparation needed to use this skill properly.

The next clever bit is that the root has only 25% chance of breaking on damage. This is a very interesting number. What it means is that if you blast the rooted mobs with an area of effect damage spell you will probably only break one or two mobs from the root. With all of a Lore-masters normal tricks any two mobs are easy meat. With five mobs rooted you could pull three or more about one time out of ten. In these cases you should probably run away and reset the pull.

Another clever feature is that Cracked Earth also includes a nasty whack of area of effect damage damage independently of the root. It takes about 15% off the health of a normal on-level mob.

As a final bit of cleverness Cracked Earth has only a ten second cool-down. This means the skill is available again for use just as the root kicks in. You can if you wish use it to apply area of effect damage to the rooted mobs. This won't extend the duration of the root unfortunately but I guess that would be overpowered. In the unlikely even that you haven't managed to slaughter them all in the original 30 second root period the short recharge time of Cracked Earth gives ample opportunity to try again.

[Aside for Nerds - you can work out the exact probabilities using a binomial probability calculation as explained here.

With 5 mobs rooted and 25% chance of breaking root on damage the chances of breaking the root are as follows:
0 mobs break: 23.7%
1 mob breaks: 39.6%
2 mobs break: 26.4%
3 mobs break: 8.8%
4 mobs break: 1.5%
5 mobs break: .1%

With 4 mobs rooted and 25% chance of breaking root on damage the chances of breaking the root are as follows:
0 mobs break: 31.6%
1 mob breaks: 42.2%
2 mobs break: 21.0%
3 mobs break: 4.7%
4 mobs break: 0.4%

End of Aside]


Marshal said...

I really like that you did the math on that :)

I agree, very clever little ability there.

mbp said...

Thanks Marshall but I can't really take credit for the Math. My own creaky knowledge of probabilities ran out of steam at two mobs but Google found that helpful page from the well brought up young ladies of Vassar with the more general formula.