Expansion // Explosion + Fork

Mana needed: {U/R}{U/R}{R}{R}, plus enough mana to cast the additional spell if needed

UR identity

Commander legal

The 2 combo pieces

• Expansion // Explosion
• Fork

What must be in place

You have a way to cast an additional instant or sorcery, or an opponent is casting one.

How to execute it

1. Cast any other instant and/or sorcery spell, or wait for an opponent to cast one.
2. Holding priority, cast Expansion by paying {U/R}{U/R}, copying the next instant or sorcery spell you cast with mana value four or less.
3. Cast Fork by paying {R}{R}, targeting the instant or sorcery spell cast in step 1.
4. The delayed trigger from Expansion triggers, copying Fork, with the copy targeting the original Fork.
5. Resolve the copy of Fork, copying Fork, with the copy targeting the original Fork.
6. Repeat step 5.

What the combo produces

• Infinite magecraft triggers