REDU format ruling
Mass Driver

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)Tribute 1 monster on your side of the field to inflict 400 points of damage to your opponent's Life Points.
Rulings
- Tributing a monster for Mass Driver is a cost.
- You can use Mass Driver's effect repeatedly in the same turn as long as you can keep paying the cost.
- The activation of Mass Driver's effect can be chained to.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.