CR vs. LA

[Crazy Scot]

Does anyone know how CR relates to LA? I know that they are usually similar to each other when adding a template, but sometimes one is slightly higher than the other.

In the DMG it says that if you add levels in a PC class to a monster you increase its CR by an equal amount. Thus a monster with CR 2 + 5 levels of Fighter would become a CR 7 creature. But what happens the other way around? If you add a CR +2 template to something, why doesn't it always relate to an equivalent LA +2?

Am I just overthinking this too much? It would make sense to me that if you add levels to something and get an equal boost to CR, then conversely if you add CR to something it should be the equivalent of adding levels to it. Can anyone out there explain why CR and LA are different sometimes?

[GoodbyeSoberDay]

A few hypotheses:

1. Wizards wanted to appear to allow the players to pick all sorts of races. In reality, they wanted to discourage monster races mechanically, and introduced inflated level adjustment for players.

2. Some monster abilities are more useful in the hands of players than in the hands of a monster. Some CR X Monster with Y class levels is probably going to be a decent challenge to a party of ECL X+Y, but that same monster as a PC with Y levels of some synergizing class could theoretically be more powerful than your average ECL X+Y character.

3. The DnD CR system is borked in general. It'll give you a good ball park, most of the time, but in general, I would adjust the CR of the encounter based on how hard it actually turned out. It's safe to swing 3 away from its listed, or even more. Just remember that lucky die rolls don't mean the monster was under-CR'd.

Whoops, didn't see the third copy of this and got semi-ninja'd by a couple people.

[Talic]

The basis for the difference between CR and LA lies partially in the criteria for overcoming a challenge. If a CR 3 monster flies away, the players win. They drove a creature off.

However, the power of flight is a carefully balanced ability, because out of combat, it overcomes many hazards and obstacles a low level party may encounter. It's generally viewed as a level 5 ability.

Additionally, certain creatures with fast healing, regeneration, blindsense, or the like can defeat many creatures in the MM's without a second thought. This is because players choose feats like Darkstalker to overcome special monster abilities. Monsters don't. They have less flexibility, and cannot be applied to as many things. You pretty much have: "advance HD", "add templates", and "add class levels".

Thus, due to the way characters can rebuild monsters for greater synergy, the corresponding LA is higher.

[sikyon]

Suppose you had the ability of Wish at will (Sp). A monster would only get to use it against a player for the duration of an encounter. A player would get to use it all day long, every day. Does it seem like the CR adjust should equal the LA? No, the CR adjust should be much lower than the LA as it has more impact for the layers than the NPC.