I read the thread about the Dwarf Mines. I'll share my approach. A Dwarf Mine with no upgrades, holding 10-15 creatures, is about as difficult to capture as a maxed-out Crypt, so it can be taken by any Castle at the beginning of the game (it's a bit harder on grass). For ranged Castles, you need to have enough ammunition. For a Swamp, for example, if you upgrade the Lizards right away, you can take it with any hero. In the worst case, you might lose part of the army from the hero on the left (I'm not considering cases where the starting army is really bad). A Dwarf Mine with 20 creatures and upgrades can be taken by any Castle at the end of the week with its native growth, if you buy all the creatures, and if the losses during the week were acceptable. To take a maxed-out Dwarf Mine, it's best to have a decent attacking stack, or enough creatures to absorb damage. In the case described by Forrest, the attacking stack was Orcs. Also, for any Castle with a strong melee 5-6 level creature (Castle, Inferno, Swamp), it's usually enough to have a few of these creatures hidden, and if the morale isn't too low, you can often succeed without losses, even if the hero isn't very strong. For a Swamp, upgrading the Lizards is almost essential; Castles like Dungeon and Necropolis usually handle a maxed-out Dwarf Mine easily. It's harder to take a Dwarf Mine on grass, but sometimes the losses aren't as important as the money. If you want to estimate very roughly, you can calculate whether the stack will be reduced by half after all your attacking creatures (including ranged damage) have attacked. If so, you can assume that the capture will be relatively safe.