ROM patcher (in browser)

Patch a disc

Two files download: the patched .bin and a matching .cue (same base name). Keep them together and point your emulator at the .cue — it references the .bin by name. Legend of Legaia is a single-track MODE2/2352 disc, so the cue is just a track header. If you'd rather reuse your original .cue, rename the patched .bin to match its FILE line.

Heads up: a full disc is ~470 MB, so patching holds a couple of copies in memory and the download is the same size — give it a moment, and use a desktop browser with enough RAM. The patched image contains Sony data: it is for your own local play, do not redistribute it. (Sharing a run is what the CLI's seed + PPF patch are for.)

What it does

This is the same randomizer / disc patcher the CLI runs, compiled to WebAssembly. Each option is a deterministic, seeded edit — same-size in place for drops / encounters / chests / steals, and a variable-length MAN rebuild for doors (the disc's total size never changes either way):

• Monster drops — reassigns the item each monster drops (and its chance). Shuffle redistributes the existing drops; Random draws from the valid item table.
• Random encounters — reassigns the monster ids in each scene's encounter formations, drawn from that scene's own monster set, so every swapped-in monster is one the scene already loads (no missing model).
• Treasure chests — reassigns the item each chest gives (the field-VM GIVE_ITEM inline operand), globally across every chest. A curated set of quest / key items (Mary's Diary, Dark Stone, the Genesis-Tree garden tools, Silver Compass, Old Rod) is kept static so progression items stay where the player expects them.
• Steal items — reassigns what each monster yields to the Evil God Icon (the static SCUS_942.54 steal table). The steal chance is always preserved — only the item changes.
• Doors / exits — reassigns where scene-transition doors lead (the field-VM 0x3F named-scene-change ops). Bidirectional re-pairs doors so you can walk back the way you came; one-way reassigns each independently. A few big overworld hubs whose data can't grow in place keep their original doors.
• House doors (experimental) — shuffles the intra-town 0x23 MOVE_TO target tiles per scene (multiset-preserving, so every target stays a valid tile), so house/interior doors lead to different rooms. The op is shared with NPC/cutscene movement, so this also scrambles some actor positions within each town — opt-in chaos.
• Starting items — replaces the new game's fixed Healing Leaf ×5 with up to five distinct random consumables (each a small random count). There is no static starting-inventory table, so this rewrites the new-game seed code in SCUS_942.54 (FUN_80034A6C) in place — a same-size patch using a packed halfword store per item, drawing from the consumable item block (Healing Leaf … Wonder Elixir) so each item belongs on the bag's consumable page.
• Unused enemies — brings back the Evil Bat, a fully-formed monster the shipped game has in its data but never places in any encounter. The battle loader streams a monster's graphics on demand by id, so adding its id to the encounter pool is enough to make it spawn. Only takes effect with Random encounters (a multiset-preserving shuffle can't introduce a new monster).
• Unused items — adds two items the game ships but never hands out: “Something Good” (a 50,000 G sell item) and an accessory that has no name in the data — the randomizer names it “Seru Bell” (a same-size SCUS_942.54 patch that repoints just that item's name pointer) so it shows a real name when it lands. Only affects the Random drop / chest / steal fills.

The same seed always produces the same patched image, so a seed (shown after patching) reproduces a run exactly. Edits that can't be re-packed into their original footprint are skipped and reported rather than corrupting the disc.

See also