The basic rule is that Counter Traps can only be used against the card they are immediately following in a chain.
So for Counter Traps:
- Chain Link 2 used against Chain Link 1 only
- Chain Link 3 used against Chain Link 2 only
- Chain Link 4 used against Chain Link 3 only
- Chain Link 5 used against Chain Link 4 only
- Chain Link 4 CANNOT be used against Chain Link 1's effect.
- Player A activates "Raigeki".
- Player B chains "Magic Jammer".
- Player A chains "Seven Tools of the Bandit".
- Player B cannot chain a second "Magic Jammer", "Magic Drain", etc. The only Counter Traps he may activate are ones that would negate the previous step ("Counter Counter", "Solemn Judgement", etc.).
This also prevents "loading on" of "Magic Drains". So you cannot chain 2 "Magic Drains" to the same Spell Card, hoping your opponent won't be able to discard two Spell Cards to save his original Spell Card.