Sersa V, I’d say that /Tunnel Rat/ should last until the beginning of the next turn in heroic tier and until the end of the encounter in paragon or epic tier. These terrain mastery boons are all swingy, though – their value really depends on the adventures’ terrain – so having it last until the beginning of the next turn at all tiers would work for some campaigns and letting it last the whole encounter would be well-balanced for others.

Good catch, though – I should have included that information.

Agree with Sersa, I love this series.

What’s the duration on /tunnel rat/’s daily power?