The engineer subclass has four tiers. These can be chosen along with your main class as you level up and cost nothing.

• IMPORTANT: The number of barrels which can be spawned in is limited to two per “barrelbringer” per round since the Client release “An Explosive Ressurection” from September 2014.
• Support items, once spawned into the game, can be picked up by any player regardless of class or tier. A newly made character can pick up barricades and place them, as long as it's helping the team.
• All support items are considered throwables. They inflict 5 blunt damage upon placement. As a result, they can be used to blow barrels and break barricades. Be mindful of where you use your support item.
• Engineering items can't be refilled in contrast to medic items (except the tome)
• Be careful when placing (and building) barricades: Placing a new one to close to another one can result in a stacked barricade, which is a) a waste of a barricade and b) forbidden. Be so kind and destroy the stacked cade if it happens.

• A Barrel has to be placed and hit to explode. This can be done by every kind of weapon, as well as medic items and barricades! Bots can hit it as well!
• A Barrel is most useful when it hits as many bots as possible. The most common way to achieve that is to use a Barrel behind barricades, as the bots often bunch at them.
• The vicinity to the bots is very important due to the limited range of a Barrel. The same applies for the timing of the exlosion. It should be used before the cades are down.
• There are mainly two situations of using a barrel:
  • As a back-up, if the cades are almost down or the danger of getting overrun is big.
  • The planned use of a Barrel, e.g. against very strong waves (mostly on Ragnarok runs)
• Don't use a Barrel without a sense behind it. You could also kill the boss of higher waves with it and they drop the most decent stuff!