Members of the University and College Union (UCU) were also refusing to work overtime, set additional work, or undertake any voluntary duties like covering timetabled classes for absent colleagues.
Staff were forming picket lines at City (Wulfruna Street) and Walsall (Gorway Road) campuses.
If the dispute is not resolved in the coming weeks, members have agreed to further strike action which could affect open days, graduation ceremonies and the clearing process.
The union is also beginning preparations for a boycott of the setting and marking of students' work to begin in the autumn.
The union has rejected a 1.1 per cent pay offer from employers, arguing that universities could afford to pay more after the pay and benefits of university leaders went up by 5.1 per cent last year.
UCU general secretary, Sally Hunt, said: "A 1.1 per cent pay offer is an insult to hardworking staff, especially in light of the five per cent pay rise vice-chancellors have enjoyed while holding down staff pay. Members have made it clear that they won't tolerate a continued squeeze on their income, pay inequality and the increasing job insecurity blighting the sector.
"It's time to invest properly in the teachers, researchers and administrators who are the backbone of our universities. Industrial action which impacts on students is never taken lightly, but members feel that they have been left with no alternative. If the employers wish to see a swift end to this dispute, and avoid further disruption, they need to come back to the table with a much-improved offer."
Protests were planned around the UK today with rallies taking place in Birmingham, Brighton, Cambridge, Glasgow, Leeds, Liverpool, London, Manchester, Newcastle and Sheffield.