There are special, elite robots in the game which you can obtain during particular events – operations.
Players are divided into 3 categories. Depending on the category, players get their own set of operations. There is only one criteria due to which the division is carried out – level of your Mechworks:
1 tier: Mechworks 4-5 ('Tarantula' and 'Inquisitor').
2 tier: Mechworks 6-8 ('Cobra', 'Malfius', 'Sentinel', 'Mauler', 'Liberator', 'Patriot', 'Godhammer').
3 tier: Mechworks 9-13 ('Overlord', 'Destroyer', 'Yeti', 'Jellywish', 'Acarus', 'Baal', 'Loki').