The Battlegroup series is the largest and longest airsoft event series organized by the Finnish Ehasa Association. The series has been organized since 2016 in the Ilveskallio training area in Hattula, Hämeenlinna. From 2019 the event was moved to Padasjoki. In 2022 we visited Juupavaara and 2023 we were back in Padasjoki. Now we have a brand new game area in Halli, Jämsä!


TSTOS 23 was attended by around 550 people. The story followed the fighting between Uusimaa and Pirkanmaa in the timeline before the events of TSTOS 20. The factions fought over the power plant and various objectives related to it and other missions. At the end of the game, there was massive fighting around the powerplant with Uusimaa, Pirkanmaa and the mysterious Cult.


TSTOS 22 was attended by more than 500 people. The story followed the fighting between Sewell Mining and the Polaris Energy. The factions fought over missiles and the ability to launch them. At the end of the event the fighting moved to the top of Juupavaara.


TSTOS 21 was attended by more than 600 people. The story followed the fighting between Hölböcorp and the EGTC, which focused on civilians and UN forces. Towards the end of the fighting, the EGTC boar of directors was overthrown which left many questions to be answered about the future.


TSTOS 20 was attended by more than 500 people. The story focused on the battles in Pirkanmaa and Uusimaa as the UN tried to secure peace among the civilian population. During the event, a new party, Hölböcorp, was introduced, and a missile was brought into the area by Hölböcorp. The missile then exploded, destroying the fighting forces of Pirkanmaa and Uusimaa.


TSTOS 19 was attended by more than 700 people and was again the longest airsoft-event in Finland, lasting more than 90 hours. In the story, the RSV device was once again controlled by various factions and eventually RSV left the area. Rumor has it that the RSV was completely destroyed and will not be seen in future.


TSTOS 18 was the third part of the game series and there were over 800 participants fighting over 90 hours. In the event both main factions strived to control RSV device. Meanwhile Remedtech developed the device further with the gold mined from gold mines in the Ilveskallio area. Because of the RSV developement, a CIA was also operating in the area trough Blue rose as a covert operation. The village and some of the gold reserver were held by the mafia in co-operation with the Ilveskallio National Guard organization.


TSTOS 17 was attended by more than 700 people and it was a day longer than the earlier event. TSTOS 17 continued the old story that, after the destruction of the hidden armor halls, factions competed against the management of fuel supplies and investigated the mysterious RSV device by solving various codes.


TSTOS Parola was the first event organized by Ehasa that lasted over the weekend and was attended by more than 600 people. TSTOS Parola started the current game story where Finland is divided into two fighting parties, Uusimaa and Pirkanmaa, who fought over the control of Ilveskallio hidden armor halls. In addition, the situation was confused by the independent Ålands special forces and the United Nations.
Information about
The Battlegroup game series

Battlegroup events, which are known by Finnish players as TSTOS (Taisteluosasto) events, have generally been attended by nearly a thousand players from Finland and abroad all the way from Sweden to Brazil. The event takes several days, without the game situation being interrupted separately. The main faction bases are calmed down at night to ensure a sufficient rest. Tens of different vehicles, such as even real life armored vehicles, off-road vehicles, SUVs and ATVs, participate in a single Battlegroup event. Most of the vehicles are involved in the game and can be destroyed by separate anti-tank weapons. Compared to similar events in the world, we are the longest event with the Swedish Berget-series. In the number of participants, we represent the biggest airsoft events in Europe. 

The content of the events

What happens in the event takes place in an imaginary world with mostly imaginary factions and nations created by the game masters. Our goal is to combine military simulation, standard airsoft, and thrilling features, creating a very cinematic and overall realistic experience. Players may appear in the event as soldiers of the fighting parties, civilians, and different in-game organizations and groups. Depending on the faction, players will be led by volunteered team and platoon leaders, company commanders and battalion commanders.


Ehasa ry works closely with other associations and federations (MPK and Reserve Sports Association), municipalities (Padasjoki, Hämeenlinna, Jämsä) and authorities (Defense Forces, Police, Rescue Service and Finnish Forest Administration). In 2016-2018 we organized cources in co-operation with the National Defense Training Association (MPK). The assistant organizers from MPK were involved in the Ehasa organization as a part of MPK’s “Basics of organizing a exercise part 2” course. The purpose of the course was to learn the organization of public events, which is comparable, for example, organizing of large military exercises. Participants in the course did benefit most from the training paid by Ehasa, such as the Finnish red cross First Aid Card and the Community Service Officer card. In 2019, we organized the first Battlegroup event in Padasjoki and also the first event without MPK cooperation because of changes in their structure.


  • 2016 +600
  • 2017 +700
  • 2018 +800
  • 2019 +700
  • 2020 +500 COVID
  • 2021 +600 COVID
  • 2022 +540 COVID
  • 2023 +550
  • From +40 to +70 player and organization owned vehicles as part of the game (2018-2023).
  • Average age of participants: >30 years (2020-2023).
  • +95% of participants are men (2018), but women are more than welcome to our event.
  • Around 20% of participants are active reservist or have shooting/hunting hobby (2018).
  • 35% of participants have taken part one or more events in abroad (2018) so our event is good start to take part similiar events outside of Finland.
  • +45% of participants have served mandatory service for 347/365 days in Finnish Defence Forces. Overall +60% have served in FDF (2018).
  • Participants have been from Sweden, Norway, Estonia, Latvia, Lithuania, Great Britain, Ireland, France, Netherlands and also from Brazil (2018-2023).
  • The highest number of foreigners has been around 90 players (2023) and each year the number of them has increased.
  • The duration of the Battlegroup event is over 90 hours
  • Ehasa members: 24 pcs.
  • In addition to the members of the Ehasa, there are assistants annually about 20.

What is Ehasa?

Ehasa or the old East Helsinki Airsoft Association is originally a registered association established in Helsinki, whose task was to organize local airsoft weekend games. Since 2010, we have moved to organize ever-growing events,which we have now organized over 30 times in different parts of South and Central Finland.

We are currently organizing the biggest events in Finland, and many enthusiasts of the sport know the reputation of Ehasa and have participated at least in one of our events. The cornerstone of our association is fast and active customer service, feedback-responsive event development, and ambition to always make events better for all of our participants.

To facilitate our operations, we have created many different programs and services, such as a kuulaportti -registration system and flag tracking system, which both are also partly available to other airsoft event organizers.

Our association consists of +20 young adults about 25-35 years of age, with the know-how of different fields and the desire and vision to take Finnish airsoft events forward. We also have few active military and military reserve members and as a result of that we have ended up in cooperation with different reserve associations.

Our regular events can be organized by ourselves, but the Battlegroup game series also requires assistance from non-members. For this reason, we have a separate recruitment page, through which you can apply as an assistant to our Battlegroup and other game series.

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