Everyone knows that teams accomplish more than individuals because with people the whole can be more than the sum of its parts. If teamwork is lacking, though, you might as well not bother with teaming up because people (and their drama) will get in each other's way.
Teams are so important that many companies pay big money send personnel to team-building exercises, like scavenger hunts, field games, escape rooms, rope courses, and so forth. Alternatively, many companies form sports leagues in the hope that teamwork on the field will translate into teamwork in the office.
Almost all such activities pit employees competitively against other employees. While some managers believe this will create a "competitive edge," you inevitably end up gloating winners and resentful losers. The last thing you want in your working team is for it to resemble a gathering of Yankees fans and Red Sox fans.
Furthermore, most of those team-building exercises favor employees who are either athletic and extroverted. As such, they tend to thrust introverts out of the loop, which is counterproductive because introverts are usually the source of much of your firm's creativity and are also the very people who tend to find teamwork challenging.
I recently stumbled across an extremely powerful and inexpensive team-building method that directs competitiveness outward rather than inward and levels the playing field for introverts. It's called "cooperative board gaming" and it's a relatively new invention that's rivaling video games in popularity among millennials.
When they hear the term "board game," most people think of chess, checkers, or monopoly--classic games that (like sports teams) have winners and losers. Cooperative board gaming is quite different. Rather than competing head-to-head or team-to-team, the team of players compete together against the GAME.
Probably the most popular cooperative board game is Pandemic, which simulates the spread of contagious diseases from city to city. Without going into detail about the mechanics (there are plenty of how-to videos on YouTube), the players use limited resources to either find cures or suppress epidemics.
As you play, the game automatically becomes more difficult. It is impossible to win a game without teamwork and the team either wins as team or loses as a team. Winning is unusual enough that it's cause for celebration. Most of the time, the team loses, but almost always as cliff-hanger.
During game play, each player moves and makes decisions separately (and "has the floor") while everyone else can advise and suggest. The game draws out introverts because everyone gets a turn being in control within the context of helping the entire team to win.
Cooperative board games don't just build teamwork; they're also a diagnostic tool to flush out team members who dominate discussions to the detriment of the team. In Pandemic, a "leader" will often emerge who tries to direct the gameplay of other players. The challenge for that "leader" is to pull back and let the team figure things out.
Pandemic creates such a powerful model for teamwork that it's being used in laboratories to study and measure intra-team behavior. According to the 2016 Proceedings of the Human Factors and Ergonomics Society Annual Meeting:
"Teamwork is paramount in most modern-day career fields [and] it is important for Human Factors students and professionals to understand the knowledge, skills, and attitudes (KSAs) requisite for excellent teamwork and to grasp the many hurdles that exist in appropriately measuring its major constructs... Pandemic forces individuals to be resourceful and work together - and exemplifies many of the behavioral, attitudinal and cognitive components of teamwork."
The beauty of cooperative board games as teambuilding tools is that, while they simulate a fictional reality, they reinforce the notion that your teams and your companies must use what resources they have to beat "the system" -- a more accurate metaphor for growing a business than head-to-head combat.
Pandemic is for two to four players, but there are other cooperative games that support larger teams. Pandemic takes about 5 minutes to learn and a typical game lasts about 40 minutes. There's also a long version of Pandemic called Pandemic Legacy, where the decisions the team makes in the beginning changes the rules for the successive games.
Note: the reason cooperative board gaming builds teamwork is because the focus is on the teammates sitting at the table with you, rather than the game itself. That's the opposite of video games (like Fortnite, for instance) where team communication is secondary to the action of the game. In other words, avoid video games; wrong teamwork model.