class monster_chance
{
public:
    int mclass;
    int level;
    int rarity;
};
class level_def
{
public:
    // The range of levels to which this def applies.
    level_range range;

    // Can be empty, in which case the default colours are applied.
    std::string floor_colour, rock_colour;
        std::string tags;
    // The probability of requesting a random vault.
    int p_vault;
    // The probability of requesting a random minivault.
    int p_minivault;
    // If non-empty, any upstair will go straight to this level.
    std::string upstair_targ, downstair_targ;
    std::vector<monster_chance> monsters;
};
class dungeon_def
{
public:
    std::string idstr;
    int id;
    std::string short_desc, full_desc;
    std::vector<level_def> level_specs;
public:
    const level_def &specs(int subdepth);
};

    const int pro_block = defender->shield_bonus();

    int pro_block = defender->shield_bonus();
    if (attacker->invisible() && !defender->can_see_invisible())
        pro_block /= 3;