The Dota AI system has 3 'levels' to it - team level, mode level and action level. The mode/action level can choose to ignore or respect the team level as it sees fit. [1] Additionally, they say under the "Coordination" section:
OpenAI Five does not contain an explicit communication channel between the heroes’ neural networks. Teamwork is controlled by a hyperparameter we dubbed “team spirit”. Team spirit ranges from 0 to 1, putting a weight on how much each of OpenAI Five’s heroes should care about its individual reward function versus the average of the team’s reward functions. We anneal its value from 0 to 1 over training.
To me, that reads as 5 individual agents, one for each character.
OpenAI Five does not contain an explicit communication channel between the heroes’ neural networks. Teamwork is controlled by a hyperparameter we dubbed “team spirit”. Team spirit ranges from 0 to 1, putting a weight on how much each of OpenAI Five’s heroes should care about its individual reward function versus the average of the team’s reward functions. We anneal its value from 0 to 1 over training.
To me, that reads as 5 individual agents, one for each character.
[1]: https://developer.valvesoftware.com/wiki/Dota_Bot_Scripting#...