Ruy Lopez long reign as World Champion". The main replies for Black are 4...d6 and 4...Bc5. In both cases, White commonly plays 5. c3. An uncommon and dubious reply is 4...Ne7, which tries to set up the Mortimer Trap. The Berlin is assigned "ECO" codes C65–C67. Code C65 covers alternatives to 4.0-0 as well as 4.0-0 Bc5. Code C66 covers 4.0-0 d6, while C67 is 4.0-0 Nxe4. Less-common third moves for Black: Ruy Lopez The Ruy Lopez (; ), also called the Spanish Opening or Spanish Game, is a chess opening characterised by the moves: The Ruy Lopez is named after 16th-century
Tactical decision game Tactical decision game A tactical decision game is a decision game that puts students in the role of the commander of a tactical unit who is faced with a challenging problem. While most tactical decision games depict problems faced by the commanders of military units, a growing number deal with the situations of types dealt with by police and firefighting organizations . The tactical decision game is known by a variety of names. These include "map problem", "tactical problem", "one-step war game", and "tactical decision exercise". Like other types of decision games, tactical decision games may either be historical or