TR3

struct TR3Savegame
{
    uint8_t saveName[75]; // ASCII C string; null-terminated (there is always random data after \0, it is ignored); for accents see String Array section of TOMBPC.DAT page
    int32_t saveNumber;
    uint8_t unknown2[135];
    // First level use block 0, second use block 1... so that at the end of the game, 
    // it sums up everything and/or checks if you found all secrets, etc
    struct
    {
        uint16_t header; // Always 0x3E8
        uint16_t ammoDesertEagle; // 65,535 means unlimited
        uint16_t ammoUzis;
        uint16_t ammoShotgun;
        uint16_t ammoMP5;
        uint16_t ammoRocket;
        uint16_t ammoHarpoon;
        uint16_t ammoGrenade;
        uint8_t smallMedipacks; // 255 means unlimited
        uint8_t largeMedipacks;
        uint8_t unknown;
        uint8_t flares;
        uint8_t unknown2[2];
        /* 0 None
         * 1 Pistols
         * 2 Desert Eagle
         * 3 Uzis
         * 4 Shotgun
         * 5 MP5
         * 6 Rocket launcher
         * 7 Grenade launcher
         * 8 Harpoon gun
         */
        uint8_t weapon; // current held weapon
        /* 00000000 00000001 Level unlocked
         * 00000000 00000010 Pistols
         * 00000000 00000100 Desert Eagle
         * 00000000 00001000 Uzis
         * 00000000 00010000 Shotgun
         * 00000000 00100000 MP5
         * 00000000 01000000 Rocket launcher
         * 00000000 10000000 Grenade launcher
         * 00000001 00000000 Harpoon gun // The presence of the new rocket launcher requires a 2-bytes field
         */
        uint16_t weapons;
        uint8_t unknown3a[2];
        uint8_t infadaStone;
        uint8_t element115;
        uint8_t isisEye;
        uint8_t daggerOfOra;
        uint8_t unknown3[20];
    } levelInitData[24]; 
    uint32_t elapsedTime; // in game ticks (1/30th of a second), so divide by 30 for time in seconds
    uint32_t ammoUsed;
    uint32_t hits;
    uint32_t distanceTraveled; // Divide by 448.18 for value in meters
    uint32_t kills;
    uint8_t secrets; // TODO: study TR3's secrets system
    uint8_t healthPacksUsed; // Divide by 2 for value. Large medipack = 1; Small = 0.5
    uint8_t levelNumber; // First level = 1
    uint8_t unknown5a[2];
    uint8_t unlimitedAmmo; // Enabled = 1
    uint8_t unknown5b[17];
    uint8_t levelNumber;
    uint8_t unknown5c[4];
    uint8_t puzzle[4]; // Corresponds to TOMBPC.DAT Puzzle & Keys entries
    uint8_t keys[4];
    // This part needs to be studied
    uint8_t unknown6[744];
    uint16_t health; // Divide by 10 for floating point value between 0 and 100; 32767 (0x7FFF) means unlimited
    uint8_t unknown7[1952];
    uint16_t air;
    uint8_t readToEOF[];
};

The levelNumber field is used for determining what level the game should load when opening the savegame. Although in TR3 you can choose in what order you go to Nevada, South Pacific and London, the order of levels here seems to be constant: