Actually, it is not, other than the fact that you have a limited time budget. In the old days, it was even simpler as you did not have to take multithreading or

Actually, it is not, other than the fact that you have a limited time budget. In the old days, it was even simpler as you did not have to take multithreading or asynchronous behaviour into consideration. (Games still often run AI and physics on hard realtime tick but it is changing.) About the only thing necessary is to stabilise pathing so that it doesn't return vastly different path on every tick and handling inter object collisions well. This may mean additionally handling swarm movement algorithms for which were already known way back in early 90s. Also in widely known books. Games like Total Annihilation handled fast movement of hundreds of units at a time with decent to good pathing and a strong enough CPU - scaling the quality of pathing automatically with available CPU power to boot. Way better than AoE and it was released at about the same time - plus it has actually smooth terrain penalty unlike AoE chunky model underneath... Three challenge was rarely algorithm but instead engineering. Time crunch was as real then as nowadays.