Fire?

[pahp]

Maybe there is a "start fire" action that burns all adjacent vegetation over many rounds, but can destroy the base and desirable plants. Maybe robot can be burned, too, so we may need a hit point scale for robot.

(I'd rather "start fire" starts a fire under the robot, but then they'd have to move the next turn, by which point they would take some burn damage, and if brush takes two turns to navigate for example, they would take more damage before leaving the fire area. The alternative is directional fire starting capability but that that seems too complicated. Not that we couldn't do it it just complicates the gameplay and decision process.)

[pahp]

Maybe weeds grow fast enough and unpredictably enough that they could lead to unintended consequences when fire spreads farther than expected.