Do alternate class skills granted by racial substitution levels stay class skills for later (non-substitution) levels?

Question

I'm trying to make an NPC that's a Fighter(5)/Knight Protector (6). According to the Complete Warrior sourcebook, the requirements for the Knight Protector prestige class are:

Base Attack Bonus: +5

Skills: Diplomacy 6 ranks, Knowledge (nobility) 4 ranks, Ride 6 ranks

Feats: (not relevant to the question)

By the time a fighter hits 5th level, they can easily meet all of those requirements except the 6 ranks in Diplomacy - they can't meet that until they're 12th level because it's a cross-class skill.

I'm looking at the Half-Elf Fighter racial substitution levels from the Races of Destiny book because they offer Diplomacy as a class skill if taken at 1st and/or 2nd level. However, the next racial substitution level is at 6th level. I know that if I took the fighter to 6th level and used the racial substitution level then I'd get the ranks in Diplomacy but I'd like to avoid that route.

My question therefore is, once the half-elf racial substitution levels make Diplomacy a class skill, does it stay a class skill for later levels of fighter? That is, if the fighter hits 5th level is their maximum number of ranks in Diplomacy 8 or only 4 ? My understanding is that for normal multiclass characters, it would be 4 but the text for racial substitution levels states specifically that taking a racial substitution level is NOT multi-classing.

I'm grateful for any help.

Answer 1

No, a substitution level change are specific to this level.

The relevant rule is on page 156 of Races of Destiny, in the introduction of Substitution Levels:

When a substitution level changes the base class’s Hit Die or class skill list, the change applies only to the specific substitution class level, not to any other class levels.

However, not all hope is lost!

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You can have 6 ranks in Diplomacy by level 3.

The relevant quote from the SRD:

Regardless of whether a skill is purchased as a class skill or a cross-class skill, if it is a class skill for any of your classes, your maximum rank equals your total character level + 3.

Therefore, since the Half-Elf substitution level grants Diplomacy as a class skill (for 1 level), forever after the maximum rank for Diplomacy is character level + 3.

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Of course, unless Diplomacy is a class skill at a specific level, it'll take 2 skill point to buy 1 rank. Still, with only 8 skill points you can buy 6 ranks in Diplomacy by being smart about when to purchase them:

• 1st level, class skill: 4 skill points, 4 ranks (max ranks 4).
• 2nd level, not class skill: 2 skill points, 5 ranks (max ranks 5).
• 3rd level, not class skill: 2 skill points, 6 ranks (max ranks 6).

So that for your specific skill goals: Diplomacy 6, Knowledge (N&R) 4, Ride 6 you need a total of 18 skill points over 5 levels, which can be achieved easily with an Intelligence modifier of +0 since the Half-Elf substitution level grants 4+Int skill points:

• 1st level (Substitution): Diplomacy 4, Knowledge (N&R) 4, Ride 4, Xxx 4.
• 2nd level: Diplomacy +1 (2 points).
• 3rd level: Diplomacy +1 (2 points).
• 4th level: Ride +2 (2 points).

If you have only 8 in Intelligence, it is still possible taking both 1st and 2nd levels of Half-Elf substitution:

• 1st level (Substitution): Diplomacy 4, Knowledge (N&R) 4, Ride 4.
• 2nd level (Substitution): Diplomacy +1, Ride +1, Xxx 1.
• 3rd level: Diplomacy +1 (2 points), Ride +1.

If you have a lower Intelligence, then I am afraid you would not gain enough skill points even with both 1st and 2nd substitution levels to achieve your goal (8 + 2 + 1 + 1 + 1 = 13).