JackknightHow it works & interactions with other cards

A Growing Steel Menace

Jackknight features a triggered ability that watches for other artifacts entering the battlefield under your control. Every time a new artifact arrives, Jackknight receives a permanent +1/+1 counter. Additionally, if the entering artifact has the Contraption subtype, Jackknight gains lifelink until the end of the turn, allowing you to stabilize your life total while pressuring your opponent.

Step-by-Step Resolution

When an artifact enters the battlefield, Jackknight's ability triggers and is placed on the stack. As the ability resolves, you first place a +1/+1 counter on Jackknight. Then, the game checks if the artifact that triggered the ability was a Contraption; if it was, the lifelink effect is applied. If multiple artifacts enter simultaneously, the ability triggers once for each artifact, and you resolve them one by one.

Common Timing Mistakes

Players often forget that Jackknight only triggers for other artifacts; it does not give itself a counter when it enters the battlefield. Furthermore, the lifelink gained from a Contraption only lasts until the end of the current turn. If you want Jackknight to have lifelink during your opponent's turn, you must have a way to make a Contraption enter the battlefield during their turn.

Strategic Deployment

Because Jackknight's growth is cumulative, it is best played early in the game before you deploy your mana rocks or artifact creatures. This maximizes the number of counters it can receive. In the late game, it serves as a massive lifelink attacker if you can consistently assemble Contraptions, turning a defensive board stall into a significant life swing.

Interaction examples

Scaling Sentinel Power

Esper Sentinel

With Jackknight on the battlefield, you cast Esper Sentinel. When Esper Sentinel enters, Jackknight's ability triggers, giving it a +1/+1 counter. This synergy is particularly strong because Jackknight grows while you add a creature that taxes your opponent's spells based on its own power.

Mana Fixing and Growth

Ornithopter of Paradise

You control Jackknight and play Ornithopter of Paradise. The Ornithopter is an artifact, so Jackknight receives a +1/+1 counter upon the Ornithopter's arrival. This allows you to develop your mana base while simultaneously building a more formidable attacker.

Double Artifact Arrival

Esper SentinelOrnithopter of Paradise

If an effect causes both Esper Sentinel and Ornithopter of Paradise to enter the battlefield at the same time while Jackknight is present, Jackknight's ability triggers twice. You will put two +1/+1 counters on Jackknight, one for each artifact.