Weevil Underwood

Second duelist of the World Tournament. Required to progress. Weevil is an anime/manga character appearing in the modern World Tournament arc — he has no connection to the Ancient Egypt storyline. His Jirai Gumo can catch unprepared players off guard.

Difficulty: Easy.

Threat Cards

• Jirai Gumo (2200 ATK)
• Cocoon of Evolution (2000 DEF)

Strategy

Another easy duel unless Weevil starts with Jirai Gumo (~15% chance). If he does, make a Twin-Headed Thunder Dragon or a 1700+ ATK monster in Mars. Good fusions include Crimson Sunbird, Flame Cerebrus, Metal Dragon, or Flame Swordsman. He can also play Neptune monsters (Great White, Toon Alligator), but they should not trouble you.

Notable Drops

Farming

When defeated in Free Duel on S/A-POW rank, he can drop Blackland Fire Dragon and Tripwire Beast. When defeated on BCD rank, he can drop Bear Trap for A-TEC strategies.

Card Pages

The AI Behavior section displays the duelist's artificial intelligence parameters including Hand Size, Max Fusion Length, Spell Probability, Attack Probability, Low LP Threshold, Critical Deck Size, and the probability distribution for decision states under both Total Domination and Lacks Domination conditions. These values determine how aggressively or defensively the duelist plays during a match.

Some duelists have the Millennium Eye ability (Heishin, Pegasus, Heishin 2nd, Seto 3rd, DarkNite, Nitemare), allowing them to see your face-down cards. The field section shows the terrain bonus that affects certain monster types.

The swords icon next to the duelist's portrait starts a practice duel against this opponent. You can test strategies, practice farming techniques, or challenge yourself against any duelist in the game. The duel uses the duelist's actual deck, AI behavior, and field terrain.

The Deck & Drops section uses tabs to switch between viewing the duelist's Deck and their three drop pools: S,A POW, S,A TEC, and B,C,D POW/TEC. Each tab shows cards with their drop weight (out of 2048) and probability percentage.

Use the search bar to find specific cards by name, ID, type, or stats. Filter by guardian stars, card type (Monster, Magic, Equip, Trap, Ritual), or any custom group using the 'Filter by group' button.

The Simulate Drop tool lets you simulate winning a duel and seeing which cards you would receive. Select a rank (S,A POW, S,A TEC, or B,C,D), choose a quantity (1, 5, 15, or 30 drops), and click the Randomize button. Each drop is drawn from the duelist's weighted card pool, with higher-weight cards appearing more frequently.

The dropdown quantity selector multiplies the number of cards you receive from a single win — drop modes x5, x15, and x30 drastically reduce farming time compared to x1 drops.

The Turn 1 Play table shows the probability of each card the duelist can play on the first turn of a duel. The data is based on ~2 billion simulated duels per duelist, run by GMS and organized by Syura. This is not official game data but should be extremely accurate.

The bold 'This or Lower' column is the most useful metric — it shows the combined chance of the duelist starting with this card's stat or any lower stat. For example, if Kaiba has a 27% 'This or Lower' for 2000 ATK, that means there's a 27% chance he starts with 2000 ATK or less. This helps you understand how rare a particular start is.

The 'This Card %' column shows the individual probability for that specific card. The 'Same Stat %' column shows the combined chance for all cards with the same max stat. The '1 in X' column shows the rarity as '1 in X duels'.

Click column headers to sort the table. Data is not available for Duel Master K since he uses a copy of your own deck.

The Simulate Turn 1 tool randomly draws cards from the duelist's turn 1 distribution. Each card's probability of being drawn matches its 'This Card %' from the table above. Select a quantity (1, 5, 15, or 30 draws) and click the Randomize button to simulate that many starting hands.

This helps you understand what cards you're most likely to face on turn 1 when dueling this opponent. High-stat cards with larger percentages will appear more often in your simulations.