Sandbags

Sandbags are the cheapest hit points in the game: one tile of wall for 40 metal, up in four seconds under an Engineer or an Engineer Boat, 500 points of structure armour, no gun, no power.

It blocks the tile it stands on to everything on the ground, and a route that used to run through it now runs round it. Where there is no way round, a column ordered through stops in front of it. It takes no production slot, and an EMP leaves it exactly as it stood.

Guns take it last. A turret behind the bags is shot at first; the bags are shot only once nothing else is in reach, and then they are shot through, which is the point of stacking them in front of a gun rather than instead of one. Shells and bombs take them apart quickly (structure armour), small arms barely scratch them, and when they go they go quietly: no charge, a puff of sand, the bags burst on the ground for a few seconds.

How to use

Lay them across the ramp, the ford or the gap in the trees an attack has to come through, one tile past your turrets' reach and inside it. A column that arrives has two choices, and both cost it: go round, under fire the whole way, or stop and grind through 500 hit points a tile while the turrets work. Leave a gap for your own army, or wall it with the rest and sell a tile when you need to march. Two rows are twice the time; a row with a gun pad every few tiles is a fortification.

They cost you the tile as well: your own units go round them too, and a factory walled in delivers nothing. Against artillery they are a sponge and nothing more, and a Drake Flame Tank pours its fire straight over them.