This card is one of the most powerful econ cards in the core set, as it' unlimited economy and this is quite rare. It's nick name is MOpus and is currently on the restricted list. On the other hand it comes with the costs of 2 MU. When you don't have your console you can't have all 3 breakers out, exception is you are Chaos Theory: Wünderkind this plays out nice in the revised core set. There are more and more consoles out that provide +2 MU, making running MOpus not such a big commitment.
When you play Magnum Opus you want to get it down Turn 1, so it's usually slotted with Self-modifying Code (install SMC, credit, credit, install MOpus, click MOpus) and often you also see Modded as it reduces the install costs significant. So running MOpus means usually mulligan for it.
With this card out, it's hard for the corp to compete the money game and often this is used for remote camping. So you are running every card installed in a remote and otherwise just click for credits. So it becomes hard for the corp to score an agenda in a remote.
You need to compare MOpus to other econ cards like Armitage Codebusting & Liberated Account and of course clicking for credits.
Compared to clicking for credits (counting the install) it pays out at click 7 assuming you have the credits to install it. Compared to Armitage it will have the same efficiency at click 11 and compared to liberated at click 12. After 20 clicks the lead is:
- Clicking = 20 creds
- Armitage = 24 creds
- Liberated = 25 creds
- MOpus = 33 creds
so you need to click MOpus a lot to make it worth playing. When you install another Liberated fast, the difference is not so significant. It also increases it's use when combined with Beth Kilrain-Chang as another click means you can click it one additional time per turn.
On top, MOpus can be protected by Sacrificial Construct and as currently most decks rely on resources it's not effected by Scarcity of Resources.
When running MOpus you usually can trash every asset installed naked like PAD Campaign so preventing the corp from getting the econ advantage.