I recently had an experience that seems to be common, judging from other posts on the internet. Using my starting Concealment, I stealthed my whole team all the way across the map to the objective, bypassing a pod along the way. However, once I neared the objective, all three pods on the map converged on it, leaving me no options but to evac or to fight the entire enemy force simultaneously.
Other posters have observed this tendency of enemies to converge if you remain concealed. Over at The enemy knows where you are in concealment on the Steam forums, Prince Ian shows this image of 5 pods all converging on his concealed ranger:
Clearly this convergence is real, and some mechanic must drive it. However, the internet is divided about what that mechanic is. From sources like the previously linked Steam forum thread and https://www.reddit.com/r/Xcom/comments/44xs8y/psa_lesserknown_pro_tips/, I've seen a couple of explanations:
Enemies can hear you when you dash, and will move to investigate the noise.
The mechanic is specifically triggered when you're close to the objective; if you get too close to the objective, the enemy sends a patrol there.
- Variant: the game tries to evenly space enemies along an invisible line that passes through both your squad and the objective. When you get close to the objective, this line becomes short, resulting in enemies converging.
Surely at least one of these claims must be true (perhaps several!), but it's difficult to tell which. Can anybody point to hard evidence - like official documentation, an analysis of the source code, or YouTube videos showing experiments designed to differentiate between these different hypotheses - that establishes what is true and what is fiction?