Initial Deck

The initial deck is the 40-card starting deck you begin your campaign with in Yu-Gi-Oh! Forbidden Memories. It is randomly generated from seven distinct pools — monster cards split by ATK + DEF thresholds, a magic card, a field spell, and an equip card — each with weighted probabilities that determine which specific cards you get.

The deck is generated once at the very start of a new game and cannot be changed until you reach the Build Deck menu. This one roll can make or break a run, which is why speedrunners evaluate it carefully before committing.

The 40 cards are drawn from seven independent pools, each with a fixed quantity and a weighted pool of possible cards:

Each pool has its own card pool with weighted probabilities. For example, the Magic Card pool contains exactly two cards — Raigeki and Dark Hole — each with a weight of 1024 out of 2048, giving a perfect 50/50 split.

The initial deck determines whether a speedrun is viable before the first duel even starts. Speedrunners look for three critical components in the starting deck:

• Raigeki — the one-sided board clear that removes all opponent monsters without touching your own. A Dark Hole (clears both sides) is a significantly worse alternative.
• A viable equip card — one of five equips that boost the Twin-Headed Thunder Dragon (THTD): Dark Energy, Beast Fangs, Horn of Light, Dragon Treasure, or Invigoration. There are 28 possible equips overall, but only these five are considered viable for the THTD meta.
• At least one Dragon and one Thunder monster — the fusion recipe for THTD (2800 ATK), the game's primary win condition.

The probability of pulling at least one of the five viable equips from the 28-card equip pool is approximately 17.86%. Combined with the 50% Raigeki chance and the need for Dragon + Thunder monsters, the overall probability of a truly optimal starting deck is extremely low — estimated around 3% — which is why runners reset repeatedly until they get a good roll.

Both are board-clearing magic cards, but they work differently and one is dramatically better for speedrunning:

• Raigeki destroys ALL opponent monsters while keeping your field intact. This is the optimal draw — you clear the AI's board and keep your fusion materials ready to attack.
• Dark Hole destroys ALL monsters on the field — both yours and the opponent's. This forces you to rebuild your board, losing critical tempo. It's considered a 'bad roll'.

In the initial deck generation, Raigeki and Dark Hole each have a weight of 1024 out of a total 2048. The split is exactly 50/50 — you have an equal chance of getting either one.

The Equip Card pool contains 28 different equip cards, each with a weight of 72 (most equips) or 80 (some cards). This means some equips are slightly more likely than others, though the difference is small.

Of these 28, speedrunners consider only five as viable for the THTD meta because they boost both ATK and DEF: Dark Energy (+500), Beast Fangs (+500), Horn of Light (+500), Dragon Treasure (+500), and Invigoration (+500). The remaining equips either boost only one stat or boost a non-Dragon type, making them suboptimal for the primary fusion strategy.

The probability of getting at least one of these five viable equips is approximately 17.86%. Even with a suboptimal equip, you can still complete the game — but the end-game boss gauntlet becomes significantly harder.

The Field Magic Card pool contains six possible field spells, each with roughly equal probability: Mountain, Umi, Yami, Sogen, Forest, and Wasteland. Each boosts a specific monster type by +500 ATK/DEF.

For the THTD meta, Mountain and Umi are preferred because Dragon and Thunder monsters benefit from them directly. Yami and Sogen also have uses, while Forest and Wasteland are generally less impactful for the standard fusion route.

The Shuffle section below the card table simulates the exact same weighted-random generation the game uses. Clicking the dice button draws 16 cards from the lowest monster pool, 16 from the 1100-1600 pool, 4 from the 1600-2100 pool, 1 from the 2100+ pool, 1 magic card, 1 field spell, and 1 equip — each selection weighted by the same probabilities used in the original game.

You can shuffle as many times as you like to see what kind of starting hands are possible. Keep track of how many tries it takes you to get Raigeki + a viable equip + a dragon and a thunder — that's the 3% roll speedrunners reset for.

Yes — every card in the initial deck can also be obtained through other means in the game. Some are available as drops from specific duelists, others can be fused or bought through the password shop. The initial deck is just your starting point; all 40 cards are obtainable through normal gameplay.