is active, which is easier against smaller shields but can be circumvented by positioning the shield with the control stick. If the shield shrinks too much, it will shatter and stun the player for a short period of time. However, turtling is still possible because of various characters who rely heavily on projectiles. Real-time strategy games A turtle strategy is commonly used in real-time strategy video games. When turtling, the player protects their territory, to the exclusion of creating forces for attacking the enemy. A turtling strategy may work because it forces the opponent to be more aggressive and constantly force him to attack the turtling player until the map is mined out and the opponent does not have any resources to replenish their forces. The most common way to turtle is to build large numbers of towers, turrets, and other defensive structures to fire on enemy units. Turtle armies may also incorporate large groups of artillery units to extend effective range and prevent opposing artillery units from attacking with impunity. The turtling strategy has some major weaknesses. First, many games have units which out-range defensive buildings (catapults, artillery, etc.) and/or short-range units which are fast enough and tough enough to rush the defenses. The turtling strategy may then collapse (especially if overly dependent on choke points) as the more aggressive player destroys one group of defenses, destroys resource-gathering and unit-building facilities in that area, and then attacks another set of defenses, etc. (assuming that the attacker has been building reinforcements in the meantime). Another serious weakness of turtling is that it prevents the turtler from spreading across the map to acquire additional resources and therefore lets the enemy use these resources to build more and often better offensive units. The seriousness of this disadvantage varies: it is most serious on maps where there are many resource patches and few opponents competing for them. Under competitive multiplayer conditions starting resources are often limited, and the turtling strategy involves devoting them all to defense while disregarding other objectives, the most important of which usually being to attack and secure other sources of income. While the turtle builds up his defensive shell, the "attacker" is free to take control of the rest of the map, providing them with an abundance of resources with which to build up a large force (including artillery which can outrange defensive structures, and superweapons, if applicable) and