A board game is a tabletop game that involves counters or pieces moved or placed on a pre-marked surface or "board", according to a set of rules. Games can be based on pure strategy, chance (e.g., rolling dice), or a mixture of the two, and usually have a goal that a player aims to achieve. Early board games represented a battle between two armies, and most modern board games are still based on defeating opposing players in terms of counters, winning position, or accrual of points (often expressed as in-game currency).