Repair

After a unit is damaged or salvaged in battle, you will generally want to repair it.

The simplest form of repair is reloading ammunition. This is instantaneous, and can be done without the services of a technician. It does cost a small amount of C-Bills, generally about 100 per ton of ammo for specialty ammunitions, or less for regular ammunition.

All other repairs will require technicians and time. Each individual repair - a given section of armour or internal, or a given critical - will require the services of a single technician as well as some amount of C-Bills. Each repair type has a base time(listed as "hours", which are RL seconds), a base cost in C-Bills, and a base roll. You can also increase the time spent and cost to reduce the roll - each +1 on the roll increases the cost somewhat and doubles the time taken. The other way to increase the roll is to use a better technician. Technicians come in four skill levels - Green, Regular, Veteran, and Elite. Each level of technician gets +1 higher rolls than the previous level, but their work costs slightly more. You can only hire Green or Regular techs, at 100 C-Bills per and 200 C-Bills per respectively - higher levels can only be gained by having them do repairs and improve their skills. Some technicians will also be lost as you do repairs, so you'll need to hire replacements occasionally. As a starting player, the usual advice is to hire 10 green technicians to start. To hire technicians, go to Campaign -> Personnel > Techs -> Hire Techs. You'll never want to fire them.

It is important to note that a failed roll has no consequences other than wasted time and money. Failed repairs do not damage the unit in any way.

The result of this mechanic is that keeping your costs low is an optimization question. It's possible to keep your rolls very low by using good techs and having them spend a while on it, but it'll cost more, and after a while diminishing returns sets in. In many cases, the lowest expected costs comes from using average-quality techs on a middling roll, instead of giving it to your elites and having them slave away for days.

You can use the specific repair option if you want to get a better feel for the system, but in practice the Bulk Repair option is best for regular use, since it calculates the expected costs of repairs for you. Bulk repair doesn't always default to the single lowest-average-cost option, but it comes pretty close, so you can use it as-is without fretting too much in most cases.