Partisans are anti-engineer for two reasons.
Firstly and most directly, they get that overkill attacking bonus against engineers, settlers, and other no-attack units (thanks Sodak, I didn't know the exact multiplier). Within a modern AI's frontiers, engineers are about the only units you'll see outside cities, and these are easy prey for the partisan. Defending against other units, engineers are actually pretty tough.
Secondly, partisans have movement freedoms that make them good pillagers, deleting the work of engineers. They are not blocked by zone of control, and treat all land squares (except railroad) as road. A partisan could, in one turn, travel by rail past an enemy's cities, go over a mountain, occupy a hill surrounded by enemy units, and pillage the mine on that hill.
Partisans are durable enough to be a chore to dislodge or hunt down. But they're cheap enough that you can make them in droves. I don't want to argue the cost effectiveness of partisans on a 'fun' thread, though. The main reason I build them is for the good of the environment. I like to return a civ's lands to primordial beauty.
Firstly and most directly, they get that overkill attacking bonus against engineers, settlers, and other no-attack units (thanks Sodak, I didn't know the exact multiplier). Within a modern AI's frontiers, engineers are about the only units you'll see outside cities, and these are easy prey for the partisan. Defending against other units, engineers are actually pretty tough.
Secondly, partisans have movement freedoms that make them good pillagers, deleting the work of engineers. They are not blocked by zone of control, and treat all land squares (except railroad) as road. A partisan could, in one turn, travel by rail past an enemy's cities, go over a mountain, occupy a hill surrounded by enemy units, and pillage the mine on that hill.
Partisans are durable enough to be a chore to dislodge or hunt down. But they're cheap enough that you can make them in droves. I don't want to argue the cost effectiveness of partisans on a 'fun' thread, though. The main reason I build them is for the good of the environment. I like to return a civ's lands to primordial beauty.