Game rules - DDM Guild

Blocked Path: If any line traced between the creature’s starting space and ending space passes
through a square that slows or prevents movement, or contains a creature (even an ally), the
charge is not allowed. The creature can ignore squares that slow movement that it actually
occupies when it starts its charge, so long as it leaves those squares with its first square of
movement. (In other words, a creature can charge out of difficult terrain so long as none of its
move is slowed by difficult terrain.)
Line of Sight: A creature can’t charge if it can’t see an enemy at the start of its turn.
Nearest Enemy Only: If anything prevents a creature from charging the nearest enemy, it
can’t charge at all.
Lost Target: If some circumstance results in the target of a charge being destroyed or moved
from its original space before the attacker makes its melee attack, the charge continues to its
original destination space. The charging creature can no longer make a melee attack, even if its
original target is still adjacent to that space.
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