{"id":1116,"date":"2026-06-29T10:42:03","date_gmt":"2026-06-28T22:42:03","guid":{"rendered":"https:\/\/thesudoku.com\/blog\/?page_id=1116"},"modified":"2026-07-08T15:49:34","modified_gmt":"2026-07-08T03:49:34","slug":"dual-medusa","status":"publish","type":"page","link":"https:\/\/thesudoku.com\/blog\/dual-medusa\/","title":{"rendered":"Dual Medusa"},"content":{"rendered":"\n<div class=\"wp-block-group content-wrapper has-base-background-color has-background has-global-padding is-layout-constrained wp-block-group-is-layout-constrained\" style=\"min-height:90vh;margin-top:var(--wp--preset--spacing--40);margin-bottom:var(--wp--preset--spacing--40);padding-top:0;padding-bottom:0\">\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-b5150c35 wp-block-group-is-layout-constrained\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:0;padding-left:var(--wp--preset--spacing--40)\">\n<p class=\"is-style-default\" style=\"font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.392), 18px);font-style:normal;font-weight:700\"><a data-type=\"page\" data-id=\"73\" href=\"https:\/\/thesudoku.com\/blog\/sudoku-rules-normal\/\">&lt; <\/a><a href=\"https:\/\/thesudoku.com\/sudoku-rules-expert\/\">Back<\/a><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-8dd13e6d wp-block-group-is-layout-constrained\" style=\"padding-right:var(--wp--preset--spacing--60);padding-left:var(--wp--preset--spacing--60)\">\n<p class=\"is-style-text-display is-style-text-display--1\" style=\"font-size:clamp(17.905px, 1.119rem + ((1vw - 3.2px) * 0.99), 28px);font-style:normal;font-weight:800\"><strong>Dual Medusa<\/strong><\/p>\n\n\n\n<p><strong>Dual Medusa<\/strong> is an advanced Sudoku solving technique that is virtually identical to the 3D Medusa. Both strategies rely on the same two-color network logic and use the exact same elimination rules. They differ in one crucial aspect only: where the coloring process begins.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The Starting Point: 3D Medusa vs. Dual Medusa<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>3D Medusa<\/strong> starts inside a single <strong>bi-value cell<\/strong> (a cell with exactly two candidates). It assigns those two candidates opposite colors, forming a strong link between two different digits within one cell.<\/li>\n\n\n\n<li><strong>Dual Medusa<\/strong> starts from a <strong>conjugate pair<\/strong> (a single digit that has exactly two possible cells remaining in a specific row, column, or 3&#215;3 box). It assigns that specific digit opposite colors in those two cells, forming a strong link for one digit across two different cells.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Building the Color Network<\/h3>\n\n\n\n<p>Once you have your starting conjugate pair colored (e.g., <strong>blue<\/strong> and <strong>green<\/strong>), spread the two colors across the Sudoku grid along every strong link. Always assign the connected candidate the opposite color:<\/p>\n\n\n\n<p><strong>Through bi-value cells:<\/strong> If your colored chain lands on a cell with only two candidates, color that cell&#8217;s second candidate the opposite color. This is the mechanism that allows the Dual Medusa chain to cross from one digit to another.from one digit to another);<\/p>\n\n\n\n<p><strong>Through conjugate pairs:<\/strong> Whenever a colored digit has only two possible spots left in any unit (row, column, or box), color the candidate in the second cell the opposite color.<\/p>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-block-group-is-layout-constrained\" style=\"padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20)\">\n<figure class=\"wp-block-image aligncenter size-full is-style-default\" style=\"margin-top:var(--wp--preset--spacing--30);margin-right:0;margin-bottom:0;margin-left:0\"><img loading=\"lazy\" decoding=\"async\" width=\"1714\" height=\"976\" src=\"https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30227.png\" alt=\"\" class=\"wp-image-1118\" style=\"aspect-ratio:1.75625098285894;object-fit:cover\" srcset=\"https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30227.png 1714w, https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30227-300x171.png 300w, https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30227-1024x583.png 1024w, https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30227-768x437.png 768w, https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30227-1536x875.png 1536w\" sizes=\"auto, (max-width: 1714px) 100vw, 1714px\" \/><\/figure>\n<\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" style=\"margin-top:var(--wp--preset--spacing--20);margin-bottom:var(--wp--preset--spacing--20)\"\/>\n\n\n\n<p>Keep extending the chain until no new candidates can be colored. The result is a single, connected network that can span several different digits across the board.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The Core Principle and Eliminations<\/h3>\n\n\n\n<p>Just like the 3D Medusa, exactly one color in your completed network is entirely correct, and the other is entirely wrong.<\/p>\n\n\n\n<p>Because the underlying logic is the same, <strong>the exact same five elimination rules apply<\/strong>:<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>A color repeated in a single cell or a single unit creates a contradiction. That entire color is false, confirming the opposite color as the solution.<\/li>\n\n\n\n<li>Any uncolored candidate that ends up seeing both colors in its unit\u2014or shares a cell containing both colors\u2014is logically trapped and can be safely eliminated.<\/li>\n<\/ol>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-block-group-is-layout-constrained\" style=\"padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20)\">\n<figure class=\"wp-block-image aligncenter size-full is-style-default\" style=\"margin-top:var(--wp--preset--spacing--30);margin-right:0;margin-bottom:0;margin-left:0\"><img loading=\"lazy\" decoding=\"async\" width=\"1714\" height=\"976\" src=\"https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30226-1.png\" alt=\"\" class=\"wp-image-1119\" style=\"object-fit:cover\" srcset=\"https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30226-1.png 1714w, https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30226-1-300x171.png 300w, https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30226-1-1024x583.png 1024w, https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30226-1-768x437.png 768w, https:\/\/thesudoku.com\/blog\/wp-content\/uploads\/2026\/06\/Group-30226-1-1536x875.png 1536w\" sizes=\"auto, (max-width: 1714px) 100vw, 1714px\" \/><\/figure>\n<\/div>\n<\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" style=\"margin-top:var(--wp--preset--spacing--20);margin-bottom:var(--wp--preset--spacing--20)\"\/>\n\n\n\n<div class=\"wp-block-group alignwide is-content-justification-space-between is-nowrap is-layout-flex wp-container-core-group-is-layout-7f2ee5f7 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--60);padding-bottom:var(--wp--preset--spacing--60);padding-left:var(--wp--preset--spacing--60)\">\n<p style=\"font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.392), 18px);font-style:normal;font-weight:600\"><a data-type=\"page\" data-id=\"447\" href=\"https:\/\/thesudoku.com\/blog\/hidden-pairs\/\">&lt; <\/a><a href=\"https:\/\/beta.thesudoku.com\/blog\/3d-medusa\/\">3D Medusa<\/a><\/p>\n\n\n\n<p style=\"font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.392), 18px);font-style:normal;font-weight:600\"><a href=\"https:\/\/thesudoku.com\/forcing-chains\/\">Forcing Chains &gt;<\/a><\/p>\n<\/div>\n<\/div>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>&lt; Back Dual Medusa Dual Medusa is an advanced Sudoku solving technique that is virtually identical to the 3D Medusa. Both strategies rely on the same two-color network logic and use the exact same elimination rules. They differ in one crucial aspect only: where the coloring process begins. The Starting Point: 3D Medusa vs. Dual [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-no-title","meta":{"footnotes":""},"categories":[116],"tags":[],"class_list":["post-1116","page","type-page","status-publish","hentry","category-master-techniques"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v26.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Dual Medusa - TheSudoku.com<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/thesudoku.com\/blog\/dual-medusa\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Dual Medusa - TheSudoku.com\" \/>\n<meta property=\"og:description\" content=\"&lt; Back Dual Medusa Dual Medusa is an advanced Sudoku solving technique that is virtually identical to the 3D Medusa. 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