Mossbridge TrollHow it works & interactions with other cards

An Immortal Guardian

The first ability of Mossbridge Troll is a static ability that creates a continuous replacement effect. Unlike other creatures that require you to pay mana to activate a regeneration shield, this Troll effectively always has one active. If it would be destroyed by lethal damage or an effect that says 'destroy,' it instead remains on the battlefield, becomes tapped, is removed from combat, and all damage is marked off it. It immediately gains a new shield after one is consumed.

Activating the Massive Growth

To activate its second ability, you must tap any number of other untapped creatures you control whose total power is 10 or greater. This is a cost, meaning your opponent cannot respond to the tapping of creatures to prevent the ability from being placed on the stack. The game only checks the power of the creatures at the exact moment you activate the ability; if their power changes later, the +20/+20 bonus remains unaffected.

Strategic Timing and Synergies

Because the +20/+20 bonus lasts until the end of the turn, you usually want to activate this during your combat phase or in response to a spell that relies on the Troll's power. Remember that Mossbridge Troll itself cannot be tapped to pay for its own ability, but if you control two copies of Mossbridge Troll, one can be tapped to provide 5 power toward the other's activation.

Common Mistakes

A frequent error is assuming that 'Regenerate' protects against being sacrificed or having toughness reduced to zero (such as through -1/-1 counters). It does not. Regeneration only replaces destruction. Additionally, note that the creatures you tap to pay for the +20/+20 bonus do not need to have been under your control since the start of your turn; unless they are attacking, 'summoning sickness' does not prevent a creature from being tapped for a cost like this.

Interaction examples

The Plant Powered Pump

Avenger of Zendikar

With Mossbridge Troll on the field, you cast Avenger of Zendikar. If you control 10 lands, you create ten 0/1 Plant tokens. By playing a land, Landfall triggers and puts a +1/+1 counter on each Plant, making them 1/1 creatures. You can now tap all ten 1/1 Plants and the 5/5 Avenger of Zendikar to satisfy the 'total power 10 or greater' cost, giving your Troll +20/+20.

The Behemoth's Stampede

Craterhoof Behemoth

If you control several small creatures and Mossbridge Troll, you can cast Craterhoof Behemoth. Its triggered ability gives all your creatures +X/+X and trample. Once that ability resolves, your creatures will likely have well over 10 total power. You can then tap those creatures to give Mossbridge Troll an additional +20/+20, resulting in a creature with roughly 45+ power and trample.