Most places in the US will have nothing about severance written down anywhere, but it’s very common to actually pay severance in a mass layoff situation (unless the whole business is going under).

In most of the developed world there is a mandatory level of severance (and companies can obviously exceed that if they want but the base amount is guaranteed). In BC it’s one week after three months (the probationary period) a second week after one year and then one additional week per year up to a maximum of eight weeks.