错误：转换为非标量类型请求

typedef struct stats {                  
    int strength;               
    int wisdom;                 
    int agility;                
} stats;

typedef struct inventory {
    int n_items;
    char **wepons;
    char **armor;
    char **potions;
    char **special;
} inventory;

typedef struct rooms {
    int n_monsters;
    int visited;
    struct rooms *nentry;
    struct rooms *sentry;
    struct rooms *wentry;
    struct rooms *eentry;
    struct monster *monsters;
} rooms;

typedef struct monster {
    int difficulty;
    char *name;
    char *type;
    int hp;
} monster;

typedef struct dungeon {
    char *name;
    int n_rooms;
    rooms *rm;
} dungeon;

typedef struct player {
    int maxhealth;
    int curhealth;
    int mana;
    char *class;
    char *condition;
    stats stats;
    rooms c_room;
} player;

typedef struct game_structure {
    player p1;
    dungeon d;
} game_structure;

这里是我有一个问题的代码：

dungeon d1 = (dungeon) malloc(sizeof(dungeon));

它给我错误“错误：转换为非标量类型请求”
有人能帮我理解为什么会这样吗？