feat: add typed scheme payload structs + field accessors

Add SchemeOptions (36B), WeaponSettings (4B), and ExtendedOptions (110B)
structs with from_bytes/to_bytes for safe typed access to .wsc payload
fields. Include V3 ROM defaults, scheme weapon order table, and 8 new
tests covering typed field access, roundtrips, and version boundaries.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

crates/openwa-types/src/address.rs

@@ -233,6 +233,21 @@ pub mod va {
     pub const SCHEME_DETECT_VERSION: u32 = 0x004D_4480;
     /// Extracts built-in schemes from PE resources to User\Schemes\ directory
     pub const SCHEME_EXTRACT_BUILTINS: u32 = 0x004D_5720;
+    /// Copies payload data + V3 defaults into scheme struct: fastcall(?, data, dest, name)
+    pub const SCHEME_INIT_FROM_DATA: u32 = 0x004D_5020;
+    /// Validates weapon ammo counts against max table (39 weapons): returns 0=ok, 1=over limit
+    pub const SCHEME_CHECK_WEAPON_LIMITS: u32 = 0x004D_50E0;
+    /// Validates V3 extended options field ranges: returns 0=valid, 1=invalid
+    pub const SCHEME_VALIDATE_EXTENDED_OPTIONS: u32 = 0x004D_5110;
+    /// Scans User\Schemes\ for {NN} name.wsc files, marks found indices in global array
+    pub const SCHEME_SCAN_DIRECTORY: u32 = 0x004D_54E0;
+
+    // === Scheme data (in .rdata/.data) ===
+
+    /// V3 extended options defaults (110 bytes), applied to V1/V2 schemes
+    pub const SCHEME_V3_DEFAULTS: u32 = 0x0064_9AB8;
+    /// Per-weapon max ammo table (39 bytes), used by CheckWeaponLimits
+    pub const SCHEME_WEAPON_AMMO_LIMITS: u32 = 0x006A_D130;
 
     // === Lobby / network ===
 

crates/openwa-types/src/scheme.rs

@@ -9,12 +9,12 @@
 ///   Bytes 5+:  Payload (size depends on version)
 ///
 /// Version → payload size:
-///   0x01 → 0xD8 bytes (216)
-///   0x02 → 0x124 bytes (292)
-///   other → version_byte as usize + 0x124 bytes
+///   0x01 → 0xD8 bytes (216): 36 options + 45 weapons × 4
+///   0x02 → 0x124 bytes (292): V1 + 19 super weapons × 4
+///   0x03 → 0x192 bytes (402): V2 + 110 bytes extended options
 ///
-/// Source: Ghidra decompilation of Scheme__Load (0x4D4CD0),
-///         Scheme__ParseFile (0x4D44F0), hex analysis of bundled .wsc files.
+/// Source: Ghidra decompilation of Scheme__ReadFile (0x4D3890),
+///         Scheme__SaveFile (0x4D44F0), worms2d.info/Game_scheme_file
 
 /// Magic header bytes for .wsc files.
 pub const SCHEME_MAGIC: [u8; 4] = *b"SCHM";
@@ -164,6 +164,715 @@ impl SchemeFile {
     }
 }
 
+// === Payload layout constants ===
+
+/// Byte offset within the payload where game options start.
+pub const OPTIONS_OFFSET: usize = 0;
+/// Size of the game options section in the payload.
+pub const OPTIONS_SIZE: usize = 36;
+/// Byte offset within the payload where V1 weapon settings start.
+pub const WEAPONS_V1_OFFSET: usize = OPTIONS_SIZE; // 36
+/// Number of weapons in V1 schemes.
+pub const WEAPONS_V1_COUNT: usize = 45;
+/// Number of super weapons added in V2.
+pub const WEAPONS_V2_COUNT: usize = 19;
+/// Total weapons in V2+ schemes.
+pub const WEAPONS_TOTAL_COUNT: usize = WEAPONS_V1_COUNT + WEAPONS_V2_COUNT; // 64
+/// Bytes per weapon entry.
+pub const WEAPON_ENTRY_SIZE: usize = 4;
+/// Byte offset where V2 super weapons start.
+pub const WEAPONS_V2_OFFSET: usize = WEAPONS_V1_OFFSET + WEAPONS_V1_COUNT * WEAPON_ENTRY_SIZE; // 216 = 0xD8
+/// Byte offset where V3 extended options start.
+pub const EXTENDED_OPTIONS_OFFSET: usize = WEAPONS_V2_OFFSET + WEAPONS_V2_COUNT * WEAPON_ENTRY_SIZE; // 292 = 0x124
+/// Size of the V3 extended options section.
+pub const EXTENDED_OPTIONS_SIZE: usize = 110; // 0x6E
+
+/// Per-weapon settings (4 bytes each in the .wsc file).
+///
+/// Weapon order in the file differs from the runtime `Weapon` enum —
+/// the .wsc uses the "scheme order" defined by the original game UI.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct WeaponSettings {
+    /// Ammo count. 0 = none, 1-10 = count, 10/0x80+ = infinite.
+    pub ammo: u8,
+    /// Power level. 0-20 (max varies by weapon).
+    pub power: u8,
+    /// Turn delay before weapon becomes available. 0 = immediate.
+    pub delay: u8,
+    /// Crate probability. 0-100 percentage.
+    pub crate_probability: u8,
+}
+
+impl WeaponSettings {
+    pub fn from_bytes(b: &[u8]) -> Self {
+        Self {
+            ammo: b[0],
+            power: b[1],
+            delay: b[2],
+            crate_probability: b[3],
+        }
+    }
+
+    pub fn to_bytes(self) -> [u8; 4] {
+        [self.ammo, self.power, self.delay, self.crate_probability]
+    }
+}
+
+/// Game options (first 36 bytes of payload).
+///
+/// These are the core game settings displayed in the scheme editor.
+/// All offsets are relative to the start of the payload (file offset 0x05).
+///
+/// Source: worms2d.info/Game_scheme_file, Ghidra analysis of Scheme__ReadFile.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct SchemeOptions {
+    /// Seconds between turns (hot-seat delay). Payload +0x00, file 0x05.
+    pub hot_seat_delay: u8,
+    /// Seconds to retreat after weapon use (grounded). Payload +0x01, file 0x06.
+    pub retreat_time: u8,
+    /// Seconds to retreat after weapon use (on rope). Payload +0x02, file 0x07.
+    pub rope_retreat_time: u8,
+    /// Display total round time on screen. Payload +0x03, file 0x08.
+    pub display_total_round_time: bool,
+    /// Enable automatic replays. Payload +0x04, file 0x09.
+    pub automatic_replays: bool,
+    /// Fall damage amount at critical velocity. Payload +0x05, file 0x0A.
+    pub fall_damage: u8,
+    /// Artillery mode (worms can't move). Payload +0x06, file 0x0B.
+    pub artillery_mode: bool,
+    /// Bounty mode marker. 0x00=unset, 0x5F/0x89=editor magic. Payload +0x07, file 0x0C.
+    pub bounty_mode: u8,
+    /// Stockpiling mode: 0=Off, 1=On, 2=Anti. Payload +0x08, file 0x0D.
+    pub stockpiling: u8,
+    /// Worm selection: 0=Sequential, 1=Manual, 2=Random. Payload +0x09, file 0x0E.
+    pub worm_select: u8,
+    /// Sudden death event: 0=RoundEnds, 1=NuclearStrike, 2=HP→1, 3=Nothing. Payload +0x0A, file 0x0F.
+    pub sudden_death_event: u8,
+    /// Water rise rate during sudden death. Payload +0x0B, file 0x10.
+    pub water_rise_rate: u8,
+    /// Weapon crate probability (-100 to 100, signed). Payload +0x0C, file 0x11.
+    pub weapon_crate_probability: i8,
+    /// Donor cards enabled. Payload +0x0D, file 0x12.
+    pub donor_cards: bool,
+    /// Health crate probability (-100 to 100, signed). Payload +0x0E, file 0x13.
+    pub health_crate_probability: i8,
+    /// Energy gained from health crates. Payload +0x0F, file 0x14.
+    pub health_crate_energy: u8,
+    /// Utility crate probability (-100 to 100, signed). Payload +0x10, file 0x15.
+    pub utility_crate_probability: i8,
+    /// Hazardous object type bitmask. Payload +0x11, file 0x16.
+    pub hazardous_object_types: u8,
+    /// Mine fuse delay in seconds. 0x80+ = random. Payload +0x12, file 0x17.
+    pub mine_delay: i8,
+    /// Dud mines (some mines don't explode). Payload +0x13, file 0x18.
+    pub dud_mines: bool,
+    /// Manual worm placement at start. Payload +0x14, file 0x19.
+    pub manual_worm_placement: bool,
+    /// Initial worm energy. 0=instant death. Payload +0x15, file 0x1A.
+    pub worm_energy: u8,
+    /// Turn time in seconds. Encoding varies by range. Payload +0x16, file 0x1B.
+    pub turn_time: u8,
+    /// Round time in minutes. 0=immediate SD. Payload +0x17, file 0x1C.
+    pub round_time: u8,
+    /// Number of round wins required to win match. Payload +0x18, file 0x1D.
+    pub number_of_wins: u8,
+    /// Blood color: false=pink, true=red. Payload +0x19, file 0x1E.
+    pub blood: bool,
+    /// Aqua Sheep mode. Payload +0x1A, file 0x1F.
+    pub aqua_sheep: bool,
+    /// Sheep Heaven mode. Payload +0x1B, file 0x20.
+    pub sheep_heaven: bool,
+    /// God Worms (infinite health). Payload +0x1C, file 0x21.
+    pub god_worms: bool,
+    /// Indestructible terrain. Payload +0x1D, file 0x22.
+    pub indestructible_land: bool,
+    /// Upgraded grenades. Payload +0x1E, file 0x23.
+    pub upgraded_grenade: bool,
+    /// Upgraded shotgun. Payload +0x1F, file 0x24.
+    pub upgraded_shotgun: bool,
+    /// Upgraded cluster bombs. Payload +0x20, file 0x25.
+    pub upgraded_clusters: bool,
+    /// Upgraded longbow. Payload +0x21, file 0x26.
+    pub upgraded_longbow: bool,
+    /// Team weapons enabled. Payload +0x22, file 0x27.
+    pub team_weapons: bool,
+    /// Super weapons enabled. Payload +0x23, file 0x28.
+    pub super_weapons: bool,
+}
+
+impl SchemeOptions {
+    /// Read options from the first 36 bytes of a payload slice.
+    pub fn from_bytes(b: &[u8]) -> Self {
+        Self {
+            hot_seat_delay: b[0],
+            retreat_time: b[1],
+            rope_retreat_time: b[2],
+            display_total_round_time: b[3] != 0,
+            automatic_replays: b[4] != 0,
+            fall_damage: b[5],
+            artillery_mode: b[6] != 0,
+            bounty_mode: b[7],
+            stockpiling: b[8],
+            worm_select: b[9],
+            sudden_death_event: b[10],
+            water_rise_rate: b[11],
+            weapon_crate_probability: b[12] as i8,
+            donor_cards: b[13] != 0,
+            health_crate_probability: b[14] as i8,
+            health_crate_energy: b[15],
+            utility_crate_probability: b[16] as i8,
+            hazardous_object_types: b[17],
+            mine_delay: b[18] as i8,
+            dud_mines: b[19] != 0,
+            manual_worm_placement: b[20] != 0,
+            worm_energy: b[21],
+            turn_time: b[22],
+            round_time: b[23],
+            number_of_wins: b[24],
+            blood: b[25] != 0,
+            aqua_sheep: b[26] != 0,
+            sheep_heaven: b[27] != 0,
+            god_worms: b[28] != 0,
+            indestructible_land: b[29] != 0,
+            upgraded_grenade: b[30] != 0,
+            upgraded_shotgun: b[31] != 0,
+            upgraded_clusters: b[32] != 0,
+            upgraded_longbow: b[33] != 0,
+            team_weapons: b[34] != 0,
+            super_weapons: b[35] != 0,
+        }
+    }
+
+    /// Serialize options back to 36 bytes.
+    pub fn to_bytes(&self) -> [u8; OPTIONS_SIZE] {
+        [
+            self.hot_seat_delay,
+            self.retreat_time,
+            self.rope_retreat_time,
+            self.display_total_round_time as u8,
+            self.automatic_replays as u8,
+            self.fall_damage,
+            self.artillery_mode as u8,
+            self.bounty_mode,
+            self.stockpiling,
+            self.worm_select,
+            self.sudden_death_event,
+            self.water_rise_rate,
+            self.weapon_crate_probability as u8,
+            self.donor_cards as u8,
+            self.health_crate_probability as u8,
+            self.health_crate_energy,
+            self.utility_crate_probability as u8,
+            self.hazardous_object_types,
+            self.mine_delay as u8,
+            self.dud_mines as u8,
+            self.manual_worm_placement as u8,
+            self.worm_energy,
+            self.turn_time,
+            self.round_time,
+            self.number_of_wins,
+            self.blood as u8,
+            self.aqua_sheep as u8,
+            self.sheep_heaven as u8,
+            self.god_worms as u8,
+            self.indestructible_land as u8,
+            self.upgraded_grenade as u8,
+            self.upgraded_shotgun as u8,
+            self.upgraded_clusters as u8,
+            self.upgraded_longbow as u8,
+            self.team_weapons as u8,
+            self.super_weapons as u8,
+        ]
+    }
+}
+
+/// Weapon order in .wsc scheme files (indices 0-63).
+///
+/// This order differs from the runtime `Weapon` enum. The scheme file uses
+/// the UI panel order established by the original game.
+///
+/// Source: worms2d.info/Game_scheme_file
+pub const SCHEME_WEAPON_ORDER: [&str; 64] = [
+    // V1 weapons (0-44)
+    "Bazooka",           // 0
+    "Homing Missile",    // 1
+    "Mortar",            // 2
+    "Grenade",           // 3
+    "Cluster Bomb",      // 4
+    "Skunk",             // 5
+    "Petrol Bomb",       // 6
+    "Banana Bomb",       // 7
+    "Handgun",           // 8
+    "Shotgun",           // 9
+    "Uzi",               // 10
+    "Minigun",           // 11
+    "Longbow",           // 12
+    "Airstrike",         // 13
+    "Napalm Strike",     // 14
+    "Mine",              // 15
+    "Fire Punch",        // 16
+    "Dragon Ball",       // 17
+    "Kamikaze",          // 18
+    "Prod",              // 19
+    "Battle Axe",        // 20
+    "Blowtorch",         // 21
+    "Pneumatic Drill",   // 22
+    "Girder",            // 23
+    "Ninja Rope",        // 24
+    "Parachute",         // 25
+    "Bungee",            // 26
+    "Teleport",          // 27
+    "Dynamite",          // 28
+    "Sheep",             // 29
+    "Baseball Bat",      // 30
+    "Flame Thrower",     // 31
+    "Homing Pigeon",     // 32
+    "Mad Cow",           // 33
+    "Holy Hand Grenade", // 34
+    "Old Woman",         // 35
+    "Sheep Launcher",    // 36
+    "Super Sheep",       // 37
+    "Mole Bomb",         // 38
+    "Jet Pack",          // 39
+    "Low Gravity",       // 40
+    "Laser Sight",       // 41
+    "Fast Walk",         // 42
+    "Invisibility",      // 43
+    "Damage x2",         // 44
+    // V2 super weapons (45-63)
+    "Freeze",            // 45
+    "Super Banana Bomb", // 46
+    "Mine Strike",       // 47
+    "Girder Starter Pack", // 48
+    "Earthquake",        // 49
+    "Scales of Justice", // 50
+    "Ming Vase",         // 51
+    "Mike's Carpet Bomb", // 52
+    "Patsy's Magic Bullet", // 53
+    "Indian Nuclear Test", // 54
+    "Select Worm",       // 55
+    "Salvation Army",    // 56
+    "Mole Squadron",     // 57
+    "MB Bomb",           // 58
+    "Concrete Donkey",   // 59
+    "Suicide Bomber",    // 60
+    "Sheep Strike",      // 61
+    "Mail Strike",       // 62
+    "Armageddon",        // 63
+];
+
+/// V3 extended options (110 bytes, payload offset 0x124).
+///
+/// Present in V3 schemes; for V1/V2, the game fills this region from
+/// ROM defaults at 0x649AB8.
+///
+/// Many fields use fixed-point 16.16 format (`Fixed`), tri-state (0/1/0x80),
+/// or small enums. See field docs for valid ranges.
+///
+/// Source: worms2d.info/Game_scheme_file, Ghidra FUN_004d5110 validation.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ExtendedOptions {
+    /// Data version (currently 0). Offset +0x00.
+    pub data_version: u32,
+    /// Constant wind enabled. Offset +0x04.
+    pub constant_wind: bool,
+    /// Wind strength (signed). Offset +0x05.
+    pub wind: i16,
+    /// Wind bias. Offset +0x07.
+    pub wind_bias: u8,
+    /// Gravity (fixed 16.16). Offset +0x08. Default 0xF5C2.
+    pub gravity: i32,
+    /// Terrain friction (fixed 16.16). Offset +0x0C. Default 0xF5C2.
+    pub terrain_friction: i32,
+    /// Rope knocking. 0xFF = use default. Offset +0x10.
+    pub rope_knocking: u8,
+    /// Blood level. 0xFF = use default. Offset +0x11.
+    pub blood_level: u8,
+    /// Unrestrict rope. Offset +0x12.
+    pub unrestrict_rope: bool,
+    /// Auto-place worms by ally. Offset +0x13.
+    pub auto_place_worms_by_ally: bool,
+    /// No-crate probability. 0xFF = ignore. Offset +0x14.
+    pub no_crate_probability: u8,
+    /// Maximum crate count. Offset +0x15.
+    pub max_crate_count: u16,
+    /// Sudden death disables worm select. Offset +0x17.
+    pub sd_disables_worm_select: bool,
+    /// Sudden death worm damage per turn. Offset +0x18.
+    pub sd_worm_damage_per_turn: u8,
+    /// Phased worms (allied). 0-3. Offset +0x19.
+    pub phased_worms_allied: u8,
+    /// Phased worms (enemy). 0-3. Offset +0x1A.
+    pub phased_worms_enemy: u8,
+    /// Circular aim. Offset +0x1B.
+    pub circular_aim: bool,
+    /// Anti-lock aim. Offset +0x1C.
+    pub anti_lock_aim: bool,
+    /// Anti-lock power. Offset +0x1D.
+    pub anti_lock_power: bool,
+    /// Worm selection doesn't end hot seat. Offset +0x1E.
+    pub worm_select_no_end_hot_seat: bool,
+    /// Worm selection is never cancelled. Offset +0x1F.
+    pub worm_select_never_cancelled: bool,
+    /// Batty rope. Offset +0x20.
+    pub batty_rope: bool,
+    /// Rope-roll drops. 0-2. Offset +0x21.
+    pub rope_roll_drops: u8,
+    /// X-impact loss of control. 0 or 0xFF. Offset +0x22.
+    pub x_impact_loss_of_control: u8,
+    /// Keep control after bumping head. Offset +0x23.
+    pub keep_control_bump_head: bool,
+    /// Keep control after skimming. 0-2. Offset +0x24.
+    pub keep_control_skimming: u8,
+    /// Fall damage triggered by explosions. Offset +0x25.
+    pub explosion_fall_damage: bool,
+    /// Explosions push all objects. Tri-state: 0/1/0x80. Offset +0x26.
+    pub explosions_push_all: u8,
+    /// Undetermined crates. Tri-state. Offset +0x27.
+    pub undetermined_crates: u8,
+    /// Undetermined fuses. Tri-state. Offset +0x28.
+    pub undetermined_fuses: u8,
+    /// Pause timer while firing. Offset +0x29.
+    pub pause_timer_while_firing: bool,
+    /// Loss of control doesn't end turn. Offset +0x2A.
+    pub loss_of_control_no_end_turn: bool,
+    /// Weapon use doesn't end turn. Offset +0x2B.
+    pub weapon_use_no_end_turn: bool,
+    /// Above option doesn't block any weapons. Offset +0x2C.
+    pub weapon_use_no_block: bool,
+    /// Pneumatic drill imparts velocity. Tri-state. Offset +0x2D.
+    pub drill_imparts_velocity: u8,
+    /// Girder radius assist. Offset +0x2E.
+    pub girder_radius_assist: bool,
+    /// Petrol turn decay (fixed 16.16 fractional part). Offset +0x2F.
+    pub petrol_turn_decay: u16,
+    /// Petrol touch decay. Offset +0x31.
+    pub petrol_touch_decay: u8,
+    /// Maximum flamelet count. Offset +0x32.
+    pub max_flamelet_count: u16,
+    /// Maximum projectile speed (fixed 16.16). Offset +0x34.
+    pub max_projectile_speed: i32,
+    /// Maximum rope speed (fixed 16.16). Offset +0x38.
+    pub max_rope_speed: i32,
+    /// Maximum jet pack speed (fixed 16.16). Offset +0x3C.
+    pub max_jet_pack_speed: i32,
+    /// Game engine speed (fixed 16.16). Offset +0x40.
+    pub game_engine_speed: i32,
+    /// Indian rope glitch. Tri-state. Offset +0x44.
+    pub indian_rope_glitch: u8,
+    /// Herd-doubling glitch. Tri-state. Offset +0x45.
+    pub herd_doubling_glitch: u8,
+    /// Jet pack bungee glitch. Offset +0x46.
+    pub jet_pack_bungee_glitch: bool,
+    /// Angle cheat glitch. Offset +0x47.
+    pub angle_cheat_glitch: bool,
+    /// Glide glitch. Offset +0x48.
+    pub glide_glitch: bool,
+    /// Skipwalking. 0/1/0xFF. Offset +0x49.
+    pub skipwalking: i8,
+    /// Block roofing. 0-2. Offset +0x4A.
+    pub block_roofing: u8,
+    /// Floating weapon glitch. Offset +0x4B.
+    pub floating_weapon_glitch: bool,
+    /// RubberWorm bounciness (fixed 16.16). Offset +0x4C.
+    pub rw_bounciness: i32,
+    /// RubberWorm air viscosity (fixed 16.16). Offset +0x50.
+    pub rw_air_viscosity: i32,
+    /// RW air viscosity applies to worms. Offset +0x54.
+    pub rw_air_viscosity_worms: bool,
+    /// RubberWorm wind influence (fixed 16.16). Offset +0x55.
+    pub rw_wind_influence: u32,
+    /// RW wind influence applies to worms. Offset +0x59.
+    pub rw_wind_influence_worms: bool,
+    /// RW gravity type. 0-3. Offset +0x5A.
+    pub rw_gravity_type: u8,
+    /// RW gravity strength (fixed 16.16). Offset +0x5B.
+    pub rw_gravity_strength: i32,
+    /// RW crate rate. Offset +0x5F.
+    pub rw_crate_rate: u8,
+    /// RW crate shower. Offset +0x60.
+    pub rw_crate_shower: bool,
+    /// RW anti-sink. Offset +0x61.
+    pub rw_anti_sink: bool,
+    /// RW remember weapons. Offset +0x62.
+    pub rw_remember_weapons: bool,
+    /// RW extended fuses/herds. Offset +0x63.
+    pub rw_extended_fuses: bool,
+    /// RW anti-lock aim. Offset +0x64.
+    pub rw_anti_lock_aim: bool,
+    /// Terrain overlap phasing glitch. Tri-state. Offset +0x65.
+    pub terrain_overlap_glitch: u8,
+    /// Fractional round timer. Offset +0x66.
+    pub fractional_round_timer: bool,
+    /// Automatic end-of-turn retreat. Offset +0x67.
+    pub auto_retreat: bool,
+    /// Health crates cure poison. 0/1/2/0xFF. Offset +0x68.
+    pub health_crates_cure_poison: i8,
+    /// RW Kaos mod. 0-5. Offset +0x69.
+    pub rw_kaos_mod: u8,
+    /// Sheep Heaven's Gate bitmask. Offset +0x6A.
+    pub sheep_heavens_gate: u8,
+    /// Conserve instant utilities. Offset +0x6B.
+    pub conserve_instant_utilities: bool,
+    /// Expedite instant utilities. Offset +0x6C.
+    pub expedite_instant_utilities: bool,
+    /// Double time stack limit. Offset +0x6D.
+    pub double_time_stack_limit: u8,
+}
+
+/// Helper: read a little-endian u16 from a byte slice.
+fn read_u16_le(b: &[u8], offset: usize) -> u16 {
+    u16::from_le_bytes([b[offset], b[offset + 1]])
+}
+
+/// Helper: read a little-endian i32 from a byte slice.
+fn read_i32_le(b: &[u8], offset: usize) -> i32 {
+    i32::from_le_bytes([b[offset], b[offset + 1], b[offset + 2], b[offset + 3]])
+}
+
+/// Helper: read a little-endian u32 from a byte slice.
+fn read_u32_le(b: &[u8], offset: usize) -> u32 {
+    u32::from_le_bytes([b[offset], b[offset + 1], b[offset + 2], b[offset + 3]])
+}
+
+impl ExtendedOptions {
+    /// Read extended options from a 110-byte slice (payload offset 0x124).
+    pub fn from_bytes(b: &[u8]) -> Self {
+        Self {
+            data_version: read_u32_le(b, 0x00),
+            constant_wind: b[0x04] != 0,
+            wind: read_u16_le(b, 0x05) as i16,
+            wind_bias: b[0x07],
+            gravity: read_i32_le(b, 0x08),
+            terrain_friction: read_i32_le(b, 0x0C),
+            rope_knocking: b[0x10],
+            blood_level: b[0x11],
+            unrestrict_rope: b[0x12] != 0,
+            auto_place_worms_by_ally: b[0x13] != 0,
+            no_crate_probability: b[0x14],
+            max_crate_count: read_u16_le(b, 0x15),
+            sd_disables_worm_select: b[0x17] != 0,
+            sd_worm_damage_per_turn: b[0x18],
+            phased_worms_allied: b[0x19],
+            phased_worms_enemy: b[0x1A],
+            circular_aim: b[0x1B] != 0,
+            anti_lock_aim: b[0x1C] != 0,
+            anti_lock_power: b[0x1D] != 0,
+            worm_select_no_end_hot_seat: b[0x1E] != 0,
+            worm_select_never_cancelled: b[0x1F] != 0,
+            batty_rope: b[0x20] != 0,
+            rope_roll_drops: b[0x21],
+            x_impact_loss_of_control: b[0x22],
+            keep_control_bump_head: b[0x23] != 0,
+            keep_control_skimming: b[0x24],
+            explosion_fall_damage: b[0x25] != 0,
+            explosions_push_all: b[0x26],
+            undetermined_crates: b[0x27],
+            undetermined_fuses: b[0x28],
+            pause_timer_while_firing: b[0x29] != 0,
+            loss_of_control_no_end_turn: b[0x2A] != 0,
+            weapon_use_no_end_turn: b[0x2B] != 0,
+            weapon_use_no_block: b[0x2C] != 0,
+            drill_imparts_velocity: b[0x2D],
+            girder_radius_assist: b[0x2E] != 0,
+            petrol_turn_decay: read_u16_le(b, 0x2F),
+            petrol_touch_decay: b[0x31],
+            max_flamelet_count: read_u16_le(b, 0x32),
+            max_projectile_speed: read_i32_le(b, 0x34),
+            max_rope_speed: read_i32_le(b, 0x38),
+            max_jet_pack_speed: read_i32_le(b, 0x3C),
+            game_engine_speed: read_i32_le(b, 0x40),
+            indian_rope_glitch: b[0x44],
+            herd_doubling_glitch: b[0x45],
+            jet_pack_bungee_glitch: b[0x46] != 0,
+            angle_cheat_glitch: b[0x47] != 0,
+            glide_glitch: b[0x48] != 0,
+            skipwalking: b[0x49] as i8,
+            block_roofing: b[0x4A],
+            floating_weapon_glitch: b[0x4B] != 0,
+            rw_bounciness: read_i32_le(b, 0x4C),
+            rw_air_viscosity: read_i32_le(b, 0x50),
+            rw_air_viscosity_worms: b[0x54] != 0,
+            rw_wind_influence: read_u32_le(b, 0x55),
+            rw_wind_influence_worms: b[0x59] != 0,
+            rw_gravity_type: b[0x5A],
+            rw_gravity_strength: read_i32_le(b, 0x5B),
+            rw_crate_rate: b[0x5F],
+            rw_crate_shower: b[0x60] != 0,
+            rw_anti_sink: b[0x61] != 0,
+            rw_remember_weapons: b[0x62] != 0,
+            rw_extended_fuses: b[0x63] != 0,
+            rw_anti_lock_aim: b[0x64] != 0,
+            terrain_overlap_glitch: b[0x65],
+            fractional_round_timer: b[0x66] != 0,
+            auto_retreat: b[0x67] != 0,
+            health_crates_cure_poison: b[0x68] as i8,
+            rw_kaos_mod: b[0x69],
+            sheep_heavens_gate: b[0x6A],
+            conserve_instant_utilities: b[0x6B] != 0,
+            expedite_instant_utilities: b[0x6C] != 0,
+            double_time_stack_limit: b[0x6D],
+        }
+    }
+
+    /// Serialize extended options to 110 bytes.
+    pub fn to_bytes(&self) -> [u8; EXTENDED_OPTIONS_SIZE] {
+        let mut b = [0u8; EXTENDED_OPTIONS_SIZE];
+        b[0x00..0x04].copy_from_slice(&self.data_version.to_le_bytes());
+        b[0x04] = self.constant_wind as u8;
+        b[0x05..0x07].copy_from_slice(&self.wind.to_le_bytes());
+        b[0x07] = self.wind_bias;
+        b[0x08..0x0C].copy_from_slice(&self.gravity.to_le_bytes());
+        b[0x0C..0x10].copy_from_slice(&self.terrain_friction.to_le_bytes());
+        b[0x10] = self.rope_knocking;
+        b[0x11] = self.blood_level;
+        b[0x12] = self.unrestrict_rope as u8;
+        b[0x13] = self.auto_place_worms_by_ally as u8;
+        b[0x14] = self.no_crate_probability;
+        b[0x15..0x17].copy_from_slice(&self.max_crate_count.to_le_bytes());
+        b[0x17] = self.sd_disables_worm_select as u8;
+        b[0x18] = self.sd_worm_damage_per_turn;
+        b[0x19] = self.phased_worms_allied;
+        b[0x1A] = self.phased_worms_enemy;
+        b[0x1B] = self.circular_aim as u8;
+        b[0x1C] = self.anti_lock_aim as u8;
+        b[0x1D] = self.anti_lock_power as u8;
+        b[0x1E] = self.worm_select_no_end_hot_seat as u8;
+        b[0x1F] = self.worm_select_never_cancelled as u8;
+        b[0x20] = self.batty_rope as u8;
+        b[0x21] = self.rope_roll_drops;
+        b[0x22] = self.x_impact_loss_of_control;
+        b[0x23] = self.keep_control_bump_head as u8;
+        b[0x24] = self.keep_control_skimming;
+        b[0x25] = self.explosion_fall_damage as u8;
+        b[0x26] = self.explosions_push_all;
+        b[0x27] = self.undetermined_crates;
+        b[0x28] = self.undetermined_fuses;
+        b[0x29] = self.pause_timer_while_firing as u8;
+        b[0x2A] = self.loss_of_control_no_end_turn as u8;
+        b[0x2B] = self.weapon_use_no_end_turn as u8;
+        b[0x2C] = self.weapon_use_no_block as u8;
+        b[0x2D] = self.drill_imparts_velocity;
+        b[0x2E] = self.girder_radius_assist as u8;
+        b[0x2F..0x31].copy_from_slice(&self.petrol_turn_decay.to_le_bytes());
+        b[0x31] = self.petrol_touch_decay;
+        b[0x32..0x34].copy_from_slice(&self.max_flamelet_count.to_le_bytes());
+        b[0x34..0x38].copy_from_slice(&self.max_projectile_speed.to_le_bytes());
+        b[0x38..0x3C].copy_from_slice(&self.max_rope_speed.to_le_bytes());
+        b[0x3C..0x40].copy_from_slice(&self.max_jet_pack_speed.to_le_bytes());
+        b[0x40..0x44].copy_from_slice(&self.game_engine_speed.to_le_bytes());
+        b[0x44] = self.indian_rope_glitch;
+        b[0x45] = self.herd_doubling_glitch;
+        b[0x46] = self.jet_pack_bungee_glitch as u8;
+        b[0x47] = self.angle_cheat_glitch as u8;
+        b[0x48] = self.glide_glitch as u8;
+        b[0x49] = self.skipwalking as u8;
+        b[0x4A] = self.block_roofing;
+        b[0x4B] = self.floating_weapon_glitch as u8;
+        b[0x4C..0x50].copy_from_slice(&self.rw_bounciness.to_le_bytes());
+        b[0x50..0x54].copy_from_slice(&self.rw_air_viscosity.to_le_bytes());
+        b[0x54] = self.rw_air_viscosity_worms as u8;
+        b[0x55..0x59].copy_from_slice(&self.rw_wind_influence.to_le_bytes());
+        b[0x59] = self.rw_wind_influence_worms as u8;
+        b[0x5A] = self.rw_gravity_type;
+        b[0x5B..0x5F].copy_from_slice(&self.rw_gravity_strength.to_le_bytes());
+        b[0x5F] = self.rw_crate_rate;
+        b[0x60] = self.rw_crate_shower as u8;
+        b[0x61] = self.rw_anti_sink as u8;
+        b[0x62] = self.rw_remember_weapons as u8;
+        b[0x63] = self.rw_extended_fuses as u8;
+        b[0x64] = self.rw_anti_lock_aim as u8;
+        b[0x65] = self.terrain_overlap_glitch;
+        b[0x66] = self.fractional_round_timer as u8;
+        b[0x67] = self.auto_retreat as u8;
+        b[0x68] = self.health_crates_cure_poison as u8;
+        b[0x69] = self.rw_kaos_mod;
+        b[0x6A] = self.sheep_heavens_gate;
+        b[0x6B] = self.conserve_instant_utilities as u8;
+        b[0x6C] = self.expedite_instant_utilities as u8;
+        b[0x6D] = self.double_time_stack_limit;
+        b
+    }
+}
+
+/// V3 extended options defaults from WA.exe ROM at 0x649AB8 (110 bytes).
+///
+/// Applied to V1/V2 schemes at struct+0x138 (payload+0x124).
+/// Dumped directly from the binary — tri-state fields use 0x80 = "engine default".
+pub const EXTENDED_OPTIONS_DEFAULTS: [u8; EXTENDED_OPTIONS_SIZE] = [
+    // +0x00                                        +0x04
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x64, 0x00, 0x0F, // data_version, const_wind, wind=100, bias=15
+    0x70, 0x3D, 0x00, 0x00, 0xC2, 0xF5, 0x00, 0x00, // gravity=0x3D70, friction=0xF5C2
+    // +0x10                                        +0x14
+    0xFF, 0xFF, 0x00, 0x01, 0x05, 0x00, 0x00, 0x00, // rope_knock=FF, blood=FF, unrestrict=0, ally=1, nocrate=5
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // sd, phased, circular, anti_lock...
+    // +0x20                                        +0x24
+    0x00, 0x00, 0x80, 0x80, 0x80, 0x01, 0x00, 0x00, // batty=0, rope_roll=0, x_impact=80, bump=80, skim=80, expl_fall=1
+    0x00, 0x80, 0x00, 0x32, 0x33, 0x1E, 0xC8, 0x00, // push_all=0, timer=80, loc=0, skim2=50... petrol_decay, touch=200
+    // +0x30                                        +0x34
+    0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x10, 0x00, // flamelet=0, proj_speed=0x200000
+    0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, // rope_speed=0x100000, jet_speed=0x50000, engine (low)
+    // +0x40                                        +0x44
+    0x80, 0x80, 0x01, 0x01, 0x01, 0x00, 0x00, 0x01, // engine (high), rope_glitch, herd, jetbungee, angle, glide, skip
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // block, float, rw_bounce...
+    // +0x50                                        +0x54
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // rw_air_visc, rw_air_worms, rw_wind...
+    0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // rw_wind_worms, rw_grav_type=1, rw_grav_str=0
+    // +0x60                                        +0x64
+    0x00, 0x80, 0x00, 0x00, 0x01, 0x00, 0x07, 0x00, // rw_crate_rate=0, shower=0x80, sink=0, remember=0, fuses=1, lock=0, overlap=7
+    0x00, 0x01, 0x00, 0x00, 0x00, 0x00,             // frac_timer=0, retreat=1, cure_poison=0, kaos=0, sheep_gate=0, conserve=0
+];
+
+// === Typed accessors on SchemeFile ===
+
+impl SchemeFile {
+    /// Get the game options from the payload.
+    pub fn options(&self) -> SchemeOptions {
+        SchemeOptions::from_bytes(&self.payload[OPTIONS_OFFSET..])
+    }
+
+    /// Get weapon settings for a weapon by scheme index (0-63).
+    ///
+    /// Indices 0-44 are V1 weapons, 45-63 are V2 super weapons.
+    /// Returns `None` if the index is out of range for this scheme version.
+    pub fn weapon(&self, scheme_index: usize) -> Option<WeaponSettings> {
+        if scheme_index >= WEAPONS_TOTAL_COUNT {
+            return None;
+        }
+        // V1 schemes only have weapons 0-44
+        if scheme_index >= WEAPONS_V1_COUNT && self.version == SchemeVersion::V1 {
+            return None;
+        }
+        let offset = WEAPONS_V1_OFFSET + scheme_index * WEAPON_ENTRY_SIZE;
+        Some(WeaponSettings::from_bytes(&self.payload[offset..]))
+    }
+
+    /// Get extended options (V3 only). Returns `None` for V1/V2 schemes.
+    pub fn extended_options(&self) -> Option<ExtendedOptions> {
+        if self.payload.len() > EXTENDED_OPTIONS_OFFSET {
+            Some(ExtendedOptions::from_bytes(
+                &self.payload[EXTENDED_OPTIONS_OFFSET..],
+            ))
+        } else {
+            None
+        }
+    }
+
+    /// Get extended options, falling back to ROM defaults for V1/V2 schemes.
+    pub fn extended_options_or_defaults(&self) -> ExtendedOptions {
+        self.extended_options()
+            .unwrap_or_else(|| ExtendedOptions::from_bytes(&EXTENDED_OPTIONS_DEFAULTS))
+    }
+
+    /// Number of weapons available in this scheme version.
+    pub fn weapon_count(&self) -> usize {
+        match self.version {
+            SchemeVersion::V1 => WEAPONS_V1_COUNT,
+            _ => WEAPONS_TOTAL_COUNT,
+        }
+    }
+}
+
 /// Error type for file-based scheme operations.
 #[derive(Debug)]
 pub enum SchemeFileError {

crates/openwa-types/tests/scheme_parse.rs

@@ -1,6 +1,8 @@
 use std::path::Path;
 
-use openwa_types::scheme::{SchemeFile, SchemeVersion, SCHEME_PAYLOAD_V1, SCHEME_PAYLOAD_V2};
+use openwa_types::scheme::{
+    SchemeFile, SchemeVersion, SCHEME_PAYLOAD_V1, SCHEME_PAYLOAD_V2, WEAPONS_V1_COUNT,
+};
 
 const FIXTURES: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/tests/fixtures");
 
@@ -54,6 +56,127 @@ fn roundtrip_shopping() {
     assert_eq!(scheme.to_bytes(), original);
 }
 
+// === Typed field accessor tests ===
+
+#[test]
+fn beginner_options() {
+    let path = Path::new(FIXTURES).join("beginner.wsc");
+    let scheme = SchemeFile::from_file(&path).unwrap();
+    let opts = scheme.options();
+
+    // Verified against hex dump of beginner.wsc payload bytes
+    assert_eq!(opts.hot_seat_delay, 10);   // 0x0A
+    assert_eq!(opts.retreat_time, 5);
+    assert_eq!(opts.rope_retreat_time, 5);
+    assert_eq!(opts.display_total_round_time, true);
+    assert_eq!(opts.automatic_replays, true);
+    assert_eq!(opts.fall_damage, 0);
+    assert_eq!(opts.artillery_mode, false);
+    assert_eq!(opts.bounty_mode, 0);
+    assert_eq!(opts.stockpiling, 1);    // On
+    assert_eq!(opts.worm_select, 1);    // Manual
+    assert_eq!(opts.sudden_death_event, 3); // Nothing
+    assert_eq!(opts.worm_energy, 150);  // 0x96
+}
+
+#[test]
+fn classic_options() {
+    let path = Path::new(FIXTURES).join("classic.wsc");
+    let scheme = SchemeFile::from_file(&path).unwrap();
+    let opts = scheme.options();
+
+    // Verified against hex dump: 05 05 05 00 01 01 00 00 00 01 02 ...
+    assert_eq!(opts.hot_seat_delay, 5);
+    assert_eq!(opts.retreat_time, 5);
+    assert_eq!(opts.rope_retreat_time, 5);
+    assert_eq!(opts.display_total_round_time, false);
+    assert_eq!(opts.automatic_replays, true);
+    assert_eq!(opts.fall_damage, 1);
+    assert_eq!(opts.artillery_mode, false);
+    assert_eq!(opts.stockpiling, 0);    // Off
+    assert_eq!(opts.worm_select, 1);    // Manual
+    assert_eq!(opts.worm_energy, 100);  // hex: 0x64
+}
+
+#[test]
+fn beginner_weapons() {
+    let path = Path::new(FIXTURES).join("beginner.wsc");
+    let scheme = SchemeFile::from_file(&path).unwrap();
+
+    // Weapon 0 = Bazooka: at payload offset 36
+    // hex bytes at file offset 0x29: 0A 03 00 00
+    let bazooka = scheme.weapon(0).unwrap();
+    assert_eq!(bazooka.ammo, 10);
+    assert_eq!(bazooka.power, 3);
+    assert_eq!(bazooka.delay, 0);
+    assert_eq!(bazooka.crate_probability, 0);
+
+    // V2 weapon: index 45 = Freeze, at payload offset 36 + 45*4 = 216
+    // Should be available for V2 scheme
+    let freeze = scheme.weapon(45);
+    assert!(freeze.is_some());
+
+    // Total weapon count for V2
+    assert_eq!(scheme.weapon_count(), 64);
+}
+
+#[test]
+fn classic_weapons_v1_limits() {
+    let path = Path::new(FIXTURES).join("classic.wsc");
+    let scheme = SchemeFile::from_file(&path).unwrap();
+
+    // V1 has 45 weapons
+    assert_eq!(scheme.weapon_count(), WEAPONS_V1_COUNT);
+
+    // Weapon 0 = Bazooka — classic has 10 ammo too
+    let bazooka = scheme.weapon(0).unwrap();
+    assert_eq!(bazooka.ammo, 10);
+
+    // V2 super weapon index should return None for V1 scheme
+    assert!(scheme.weapon(45).is_none());
+    assert!(scheme.weapon(63).is_none());
+}
+
+#[test]
+fn weapon_out_of_range() {
+    let path = Path::new(FIXTURES).join("beginner.wsc");
+    let scheme = SchemeFile::from_file(&path).unwrap();
+    assert!(scheme.weapon(64).is_none());
+    assert!(scheme.weapon(100).is_none());
+}
+
+#[test]
+fn options_roundtrip() {
+    let path = Path::new(FIXTURES).join("beginner.wsc");
+    let scheme = SchemeFile::from_file(&path).unwrap();
+    let opts = scheme.options();
+    let serialized = opts.to_bytes();
+    assert_eq!(&serialized[..], &scheme.payload[..36]);
+}
+
+#[test]
+fn v1_no_extended_options() {
+    let path = Path::new(FIXTURES).join("classic.wsc");
+    let scheme = SchemeFile::from_file(&path).unwrap();
+    assert!(scheme.extended_options().is_none());
+
+    // But defaults should still work
+    let defaults = scheme.extended_options_or_defaults();
+    assert_eq!(defaults.data_version, 0);
+}
+
+#[test]
+fn v2_super_weapons_zeroed_region() {
+    // In the beginner.wsc V2 file, super weapons after the used ones should exist
+    let path = Path::new(FIXTURES).join("beginner.wsc");
+    let scheme = SchemeFile::from_file(&path).unwrap();
+
+    // Armageddon is weapon index 63 (last V2 super weapon)
+    let armageddon = scheme.weapon(63).unwrap();
+    // It should be parseable (values may be zero)
+    let _ = armageddon.ammo;
+}
+
 /// Parse all .wsc files from the game directory if available.
 #[test]
 fn parse_all_game_schemes() {

docs/re-notes/configuration.md

@@ -80,14 +80,100 @@ Binary format, variable length. Contains visual/audio theme settings.
 3. Calls `Frontend__SaveTheme` (0x490E60) with path `"data\current.thm"`
 4. Calls `FrontendChangeScreen` to navigate away
 
-## Weapon Schemes
-
-Stored as `.wsc` files under `User\Schemes\`.
-
-| Function | Address | Path Pattern |
-|----------|---------|-------------|
-| `Scheme__Load` | 0x4D4CD0 | `User\Schemes\%s.wsc` |
-| `Scheme__LoadNumbered` | 0x4D4E00 | `User\Schemes\{%02d} %s.wsc` |
+## Weapon Schemes (.wsc)
+
+Stored as `.wsc` files under `User\Schemes\`. Full format spec: [worms2d.info/Game_scheme_file](https://worms2d.info/Game_scheme_file).
+
+### Functions
+
+| Function | Address | Signature | Notes |
+|----------|---------|-----------|-------|
+| `Scheme__ReadFile` | 0x4D3890 | stdcall(dest, path, flag, out_ptr) → u32, RET 0x10 | Reads .wsc into dest+0x14 |
+| `Scheme__SaveFile` | 0x4D44F0 | thiscall(this, name, flag), RET 0x8 | Writes struct to .wsc |
+| `Scheme__DetectVersion` | 0x4D4480 | Uses ESI (non-standard) → 1/2/3 | Compares V3 extension bytes |
+| `Scheme__FileExists` | 0x4D4CD0 | stdcall(name) → 0/1, RET 0x4 | Path: `User\Schemes\%s.wsc` |
+| `Scheme__FileExistsNumbered` | 0x4D4E00 | stdcall(...) | Path: `User\Schemes\{%02d} %s.wsc` |
+| `Scheme__InitFromData` | 0x4D5020 | fastcall(?, data, dest, name) | Copies payload + V3 defaults |
+| `Scheme__CheckWeaponLimits` | 0x4D50E0 | — → 0/1 | Validates ammo vs max table (39 weapons) |
+| `Scheme__ValidateExtendedOptions` | 0x4D5110 | Uses EAX → 0/1 | V3 field range checks |
+| `Scheme__ScanDirectory` | 0x4D54E0 | — | Finds `{NN} name.wsc` files |
+| `Scheme__ExtractBuiltins` | 0x4D5720 | — | Extracts PE resources (IDs 0x3CA-0x3D6) |
+
+### Data
+
+| Symbol | Address | Size | Notes |
+|--------|---------|------|-------|
+| `SCHEME_V3_DEFAULTS` | 0x649AB8 | 110 bytes | Default extended options for V1/V2 |
+| `SCHEME_WEAPON_AMMO_LIMITS` | 0x6AD130 | 39 bytes | Max ammo per weapon (V1 set) |
+
+### File Format
+
+Binary, little-endian. Header: `"SCHM"` (4 bytes) + version byte (1 byte) + payload.
+
+| Version | Payload | Total | Content |
+|---------|---------|-------|---------|
+| V1 (0x01) | 0xD8 (216) | 221 | 36 options + 45 weapons × 4 |
+| V2 (0x02) | 0x124 (292) | 297 | V1 + 19 super weapons × 4 |
+| V3 (0x03) | 0x192 (402) | 407 | V2 + 110 extended options |
+
+### Payload Layout
+
+**Game Options (36 bytes, payload +0x00):**
+
+| Offset | Size | Field | Notes |
+|--------|------|-------|-------|
+| +0x00 | 1 | hot_seat_delay | Seconds between turns |
+| +0x01 | 1 | retreat_time | Seconds after weapon use |
+| +0x02 | 1 | rope_retreat_time | Seconds after rope weapon use |
+| +0x03 | 1 | display_total_round_time | bool |
+| +0x04 | 1 | automatic_replays | bool |
+| +0x05 | 1 | fall_damage | Damage at critical velocity |
+| +0x06 | 1 | artillery_mode | bool |
+| +0x07 | 1 | bounty_mode | 0x00/0x5F/0x89 |
+| +0x08 | 1 | stockpiling | 0=Off, 1=On, 2=Anti |
+| +0x09 | 1 | worm_select | 0=Sequential, 1=Manual, 2=Random |
+| +0x0A | 1 | sudden_death_event | 0=RoundEnds, 1=Nuke, 2=HP→1, 3=Nothing |
+| +0x0B | 1 | water_rise_rate | Flooding speed |
+| +0x0C | 1 | weapon_crate_probability | i8, -100 to 100 |
+| +0x0D | 1 | donor_cards | bool |
+| +0x0E | 1 | health_crate_probability | i8 |
+| +0x0F | 1 | health_crate_energy | Energy from health crate |
+| +0x10 | 1 | utility_crate_probability | i8 |
+| +0x11 | 1 | hazardous_object_types | Bitmask |
+| +0x12 | 1 | mine_delay | i8, seconds (0x80+=random) |
+| +0x13 | 1 | dud_mines | bool |
+| +0x14 | 1 | manual_worm_placement | bool |
+| +0x15 | 1 | worm_energy | 0=instant death |
+| +0x16 | 1 | turn_time | Seconds |
+| +0x17 | 1 | round_time | Minutes (0=immediate SD) |
+| +0x18 | 1 | number_of_wins | Rounds to win match |
+| +0x19 | 1 | blood | false=pink, true=red |
+| +0x1A | 1 | aqua_sheep | bool |
+| +0x1B | 1 | sheep_heaven | bool |
+| +0x1C | 1 | god_worms | bool |
+| +0x1D | 1 | indestructible_land | bool |
+| +0x1E | 1 | upgraded_grenade | bool |
+| +0x1F | 1 | upgraded_shotgun | bool |
+| +0x20 | 1 | upgraded_clusters | bool |
+| +0x21 | 1 | upgraded_longbow | bool |
+| +0x22 | 1 | team_weapons | bool |
+| +0x23 | 1 | super_weapons | bool |
+
+**Per-Weapon (4 bytes each, payload +0x24):**
+
+`[ammo, power, delay, crate_probability]` — 45 weapons (V1), 64 weapons (V2+).
+
+**V3 Extended Options (110 bytes, payload +0x124):**
+
+Physics (gravity, friction, wind), RubberWorm modifiers, glitch toggles, and gameplay extensions. See `scheme.rs::ExtendedOptions` for full field list. Uses fixed-point 16.16 and tri-state (0/1/0x80) types.
+
+### Callers of Scheme__ReadFile
+
+| Address | Context |
+|---------|---------|
+| 0x4A1D18 | Frontend/options dialog |
+| 0x4B4B92 | Multiplayer scheme loading |
+| 0x4CC425 | Mission/campaign loading |
 
 ## Data Files