Siege Modification

Oracle Text

Enchant creature or Vehicle

As long as enchanted permanent is a Vehicle, it's a creature in addition to its other types.

Enchanted creature gets +3/+0 and has first strike.

Card Rulings

2/9/2017 If Siege Modification becomes unattached from a Vehicle that’s attacking or blocking, that Vehicle will be removed from combat unless another effect (such as its crew ability) is also making it a creature.

Additional Information