Arcbound SlithHow it works & interactions with other cards

Understanding Combat Growth and Modular

Arcbound Slith has two distinct abilities. First, whenever it deals combat damage to a player, it gains a +1/+1 counter. Second, it features Modular 1, meaning it enters the battlefield with a +1/+1 counter and can pass its counters to another artifact creature when it dies. Note that the combat damage trigger only fires if the damage is dealt to a player; dealing damage to creatures or planeswalkers will not result in a counter.

Step-by-Step Resolution

When Arcbound Slith enters the battlefield, it arrives with one +1/+1 counter immediately. During the combat phase, if it is unblocked and deals damage to an opponent, its triggered ability goes on the stack and resolves to add another counter. If the Slith is destroyed, its Modular ability triggers. You choose a target artifact creature you control; as that ability resolves, you may move every +1/+1 counter that was on the Slith onto that target. If the Slith had -1/-1 counters that caused its toughness to be 0, the Modular ability still checks how many +1/+1 counters it had at the moment it left the battlefield.

Common Mistakes

Players often forget that Modular is optional ('you may') and that it can only target artifact creatures. You cannot put the counters on a non-artifact creature or an artifact that isn't currently a creature. Additionally, remember that the combat damage trigger and the Modular trigger are separate; if the Slith dies during combat simultaneously with dealing damage (e.g., via first strike or a trade), the timing of when counters are added or moved depends strictly on when the Slith actually leaves the battlefield.

Strategic Deployment

Play Arcbound Slith early to maximize its growth potential. Because it is an artifact, it benefits from cost reducers and provides a 'safety net' for your other artifacts. If your opponent attempts to destroy it, they risk making your other artifact creatures even more dangerous by allowing the Modular ability to resolve.

Interaction examples

Efficient Casting

Foundry Inspector

With Foundry Inspector on the battlefield, the cost to cast Arcbound Slith is reduced by {1}, allowing you to play it for just {1} mana. Once it enters, it still receives its Modular 1 counter, making it a 2/2 for a very low investment.

Passing the Torch

Ornithopter of Paradise

If Arcbound Slith has attacked and dealt damage twice, it will have three +1/+1 counters total (one from Modular, two from combat). If your opponent destroys the Slith, you can use the Modular trigger to put all three counters onto Ornithopter of Paradise. This transforms your mana-producing flyer into a 3/5 threat with Flying.