REDU format ruling
Backup Soldier

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)While there are 5 or more monsters in your Graveyard: Target up to 3 non-Effect Monsters with 1500 or less ATK in your Graveyard; add them to your hand.
Rulings
Activate only if there are 5 or more monsters in your GY. Add up to 3 non-Effect Monsters with 1500 or less ATK from your GY to your hand.
- This effect selects up to 3 targets. You can even target Gemini, Fusion, and Synchro monsters.
- If you have 4 Effect Monsters and 1 Normal Monster with 1500 ATK in your GY, you can activate this card and return the 1 Normal Monster to your hand.
- If you have 5 Normal Monsters in your GY, you can activate Backup Soldier and chain a second Backup Soldier before the first resolves, because the 5 monster requirement only needs to be fulfilled at activation. This would allow you to put all 5 monsters in your hand, 3 with the first Backup Soldier and 2 with the second.
- If your opponent activates Delinquent Duo and you chain Backup Soldier with 2 pieces of Exodia and retrieve the other 3 from your GY you win the Duel before you have to discard for Delinquent Duo. This is because you check for victory conditions in between steps in a chain, (but not in between two separate effects of a single card like Graceful Charity).
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.