 Some level types can even be extended indefinitely, with each iteration requiring an exponentially growing number of moves and pushes.Skilled human players rely mostly on heuristics and are usually able to quickly discard a great many futile or redundant lines of play by recognizing patterns and subgoals, thereby drastically reducing the amount of search.Some "Sokoban" puzzles can be solved automatically by using a single-agent search algorithm, such as IDA*; enhanced by several techniques that make use of domain-specific knowledge.