Chess of the position. Weaknesses in the pawn structure, such as isolated, doubled, or backward pawns and , once created, are often permanent. Care must therefore be taken to avoid these weaknesses unless they are compensated by another valuable asset (for example, by the possibility of developing an attack). A chess opening is the group of initial moves of a game (the "opening moves"). Recognized sequences of opening moves are referred to as "openings" and have been given names such as the Ruy Lopez or Sicilian Defense. They are catalogued in reference works such as the "Encyclopaedia of Chess Openings". There
Tactical role-playing game planned MMORPG that would have featured tactical combat, had development not been cancelled in 2006. "Gunrox" (2008), "Poxnora" (2006) and "Wakfu" (2012) are some other recent examples. Many tactical RPGs can be both extremely time-consuming and extremely difficult. Hence, the appeal of most tactical RPGs is to the hardcore, not casual, computer and video game player. Traditionally, tactical RPGs have been quite popular in Japan but have not enjoyed the same degree of success in North America and elsewhere. However, the audience for Japanese tactical RPGs has grown substantially in the West since the mid-90s, with PS1 and PS2 titles