How does CR adjustment work in PF?

After sifting through, I found that you can create a character as a wight with a template, with the following adjustments;]
CR: As base creature +1

This is fan-created
content or a fan conversion.
See here for more details.

Alignment: Always Lawful Evil.

Type: The creature's type changes to undead (augmented). Do not recalculate class Hit Dice, BAB, or saves.

Senses: A wight gains darkvision 60 ft.

Armor Class: Natural armor improves by +4
Hit Dice: Change all racial Hit Dice to d8s. Class Hit Dice are unaffected. As undead, wights use their Charisma modifier to determine bonus hit points (instead of Constitution).

Weaknesses: A wight gains the following weakness.

Resurrection Vulnerability (Su) A raise dead or similar spell cast on a wight destroys it (Will negates). Using the spell in this way does not require a material component.

Melee: A wight gains a slam attack if it does not already have one (see Natural Attacks). Its slam also causes energy drain (see below).

Special Attacks: Save DCs are equal to 10+1/2 the wight’s HD + the wight’s Cha modifier.

Energy Drain (Su) A creature hit by a wight's slam (or other natural weapon) gains a negative level.

Special Abilities: A wight gains the following.

Create Spawn (Su) Any humanoid creature that is slain by a wight becomes a wight itself in only 1d4 rounds. Spawn so created are less powerful than typical wights, and suffer a –2 penalty on all d20 rolls and checks, as well as –2 hp per HD. Spawn are under the command of the wight that created them and remain enslaved until its death, at which point they lose their spawn penalties and become full-fledged and free-willed wights. They do not possess any of the abilities they had in life.

Abilities Increase from the base creature as follows: Str +2, Dex +2, Wis +2, Cha +4. As undead creatures, wights have no Con score.

Skills Wights gain a +8 racial modifier to Stealth checks.

Feats Wights gain the Blind-Fight feat, assuming the base creature doesn’t already have the feat.




It says this is a fan conversion, but the original entry has pretty much all of this, but the Wight seems to have 4 RHD. Would I play this as an ECL 5 creature (4 RHD + 1 CR) before class levels?

I there's a key piece of information that is missing here. Are you trying to play a Wight character? If so, you need to work that out with your GM - the Wight template is NOT intended to allow PCs to play Wights.

If the Wight in question is supposed to be a monster, on the other hand, simply take the monster's base CR(For example, CR7 for Hill Giants) and add 1 to it.