Collection of criteria that a bool CriteriaAreMet method checks

I'm trying to design a simple skill system for a game. In each game loop I want to iterate through all the player's skills and determine whether any should advance.

I thought I'd construct something like below. I don't know what type of component to use for the list of advancement criteria in the Skill class.

I'm not married to this approach but I'm hoping to avoid writing a separate concrete class for each skill; there will be dozens, and I plan to use this as a library.

public class Player
{
    public List<Skill> Skills { get; }
}

public class Skill
{
    public List<???> AdvancementCriteria { get; }

    bool AdvancementCriteriaMet()
    {
        // Iterate through AdvancementCriteria
        // if any return FALSE then return FALSE
    }

    void Advance()
    {
        // Advance the skill
    }

    public void Update()
    {
        if(AdvancementCriteriaMet) Advance();
    }
}

public class GameLoop
{
    Player player = new Player();

    void Loop()
    {
        foreach(Skill s in player.Skills) s.Update();
    }
}

EDIT for clarification: I want to be able to assert things as criteria like:

• Athletics skill: Player is jumping || Player is running || Player is swimming
• Sword skill: Player.InCombat == true &&a开发者_开发知识库mp; Player.Wield.WieldType == Sword
• First Aid skill: BandagesUsedCurrent > BandagesUsedPrevious

---

You can use a delegate, with a set of lambda expressions.

public delegate bool AdvancementCriterion(Player player);
public List<AdvancementCriterion> AdvancementCriteria { get; }

AdvancementCriteria.Add(p => p.Thingy > x);

if (AdvancementCriteria.All(c => c(Player))

---

public List<Func<bool>> AdvancementCriteria { get; }