To Force (Forcing) is employing any strategy that - as the name implies - forces the opponent to make a certain tech choice or in-game decision; the consequences of not making this choice can range from incurring a major disadvantage to outright losing. The goal is to limit the opponent's possibilities and thus limit the number of scenarios you must worry about.
Forcing is when one player chooses to do one strategy that "forces" the other player to respond in a limited number of ways, otherwise face severe crippling or outright lose the game.
An example: Any fast pool build can be considered a force because if the other player does not respond in a set manner (making something to defend the early aggression), then they will lose. Against any fast-expanding or quick-teching opponent, a fast pool build will yield a near-instant victory. The opponent, after seeing your 6/8/9 Pool build, must cancel any fast expansion plans and bulk up units to defend with. the fast pool "forces" your opponent fore-go any econ-oriented build, and instead do a more military oriented build.
- Early Mutalisks can force a high Marine count if the opponent has not reached Starport or Armory tech yet. With enough Muta pressure, the opponent will build up a considerable amount of Marines and also waste several hundred minerals on Missile Turrets in and around their bases. If they do not react in this fashion, Muta harass will eat away at their economy for the remainder of the game. However, if they respond with large amounts of Marines, this makes them highly susceptible to Baneling attacks. Thus, the Mutalisk/Speedling/Baneling strategy is a good force against Terran.
- The Roach Feint is a technique that forces the opponent to rush to get Immortals by presenting decent Roach numbers early on. Following that, by abandoning Roach production and switching to Zerglings and Hydralisks, you capitalize on having forced Immortals, since Immortals are ineffective against these units.
- A fast Baneling Nest, which is currently the hallmark of ZvZ play, is a force. If the opponent does not create Banelings or Roaches quickly, they will leave their Drones highly vulnerable to a Baneling run-by, crippling their economy.
- Dark Templar can be used as a semi-force. Instead of forcing a certain tech choice, they force wasted Scanner Sweeps or wasted minerals on Missile Turrets. Most opponents will react in this fashion, rather than leave themselves exposed to the possibility of DT harass.
- Early Void Ray (hallucinated or real), can force your enemy to a high number of Marines. This also may lead your enemy to building of a lot of Missile Turret. A strong Marine force then can be exploited by Colossus.
- Like the other mirror matchups, PvP revolves around a single unit - the Colossus. Most PvP matches become a race to the Colossus, and whichever player has a higher Colossus count (with Extended Thermal Lances) has the advantage due to their long range and strength. Both players are forced into maintaining constant Colossus output then, for fear of falling behind.
- 2 Gate is an example of a "soft" Force. It counts on your opponent overreacting to either seeing two Gateways, or the large number of Zealots pushing into your opponent's base; your opponent will then try to quickly build a Roach Warren to counter the Zealot pressure.
- A simple exploitation of this force is to quickly move to Stalker production. Stalkers outrange Roaches and move faster as well; building a Robotics Facility for a fast Immortal is an option if you sense mass Roach production.
- Another option, which can be a little riskier, is getting a fast Stargate and Void Ray. The Zerg player's only anti-air will be one Queen, which will quickly die against a single Void Ray (if charged). From there, that Void Ray can have free rein of the Zerg base.
- Another Force which the Protoss can utilize is to open with a couple of Void Rays. If there is sufficient Void Ray pressure, the Zerg will be Forced to produce Hydralisks against the Void Rays. The Protoss can then switch to Colossus which is effective against Hydralisks.
- Currently, TvT games revolve around Siege Tanks and Vikings, using the Vikings to provide sight for the Tanks. As such, whichever player has the higher Viking count will survive the air battle, and will have greater sight range. Thus, both players are forced into continuous Viking production for fear of losing air control.
- Due to the Marauder's effectiveness versus Gateway units like the Zealot and Stalker, if a Protoss player is faced with large Marauder counts they will opt for a quick Robotics Facility to begin pumping Immortals. Thus, a "Marauder Feint" can work like the aforementioned Roach Feint by forcing Robo tech from the Protoss opponent.