Obstruction
In a game of competition, co-players may employ a strategy of obstruction in order to gain an advantage. Obstruction happens in the physical domain, for example by blocking an opponent's access to a QR tag.
Obstruction may occur without it having been planned for. If it is not designed into the game, it may emerge depending on the profile players and on the level of competition competition.
Example
In CarnivalScrabble, the organizers feared that players would remove QR tags completely after they have scanned them in order to prevent opposing teams from finding and scanning them. During the initial phase of the game this behaviour was actually observed, despite warnings that have been issued prior to the game that this behaviour would lead to either disqualification or not counting the specific tag in the final score calculation. In the specific game the level of competition was very high though.
In the case of museumscrabble, where the players were kids aged 10-12 years, players blocked opponents from scanning RFID tags by placing themselves in front of the exhibits.