Monthar
Deity
In two different games an embarked AI worker went around plundering my trade routes. I don't know if any other civilian units can plunder trade routes, nor if it's just the sea trade routes or both land and sea. I wasn't able to get any of my workers in place to attempt to plunder, so I don't know if it's just an AI thing or not.
If all civilians are able to plunder, that makes missionaries one of the best units to go a plundering land trade routes with as long as they don't end their turn inside the enemy's lands. Couple this with the AI's insane bonuses and massive missionary spam at the higher difficulty levels, this can get out of hand very quickly.
Even if this is not a bug, I feel civilian units should not be allowed to plunder trade routes. I also feel embarked units should not be allowed to plunder sea trade routes even if it is a military unit. All plundering should be done by military units only and only in the realm the unit is designed for, ie. land units plunder land trade routes and naval units plunder sea trade routes.
If all civilians are able to plunder, that makes missionaries one of the best units to go a plundering land trade routes with as long as they don't end their turn inside the enemy's lands. Couple this with the AI's insane bonuses and massive missionary spam at the higher difficulty levels, this can get out of hand very quickly.
Even if this is not a bug, I feel civilian units should not be allowed to plunder trade routes. I also feel embarked units should not be allowed to plunder sea trade routes even if it is a military unit. All plundering should be done by military units only and only in the realm the unit is designed for, ie. land units plunder land trade routes and naval units plunder sea trade routes.