Stumble Rules

[Phillus]

Person I was playing against said you can move after your creatures action phase when stumble is on them.
>Activate Stumble
>Westlock Attack my Skeletal Sentry
>End of Westlock's action phase so Westlocks moves.

[echephron]

no.

Action phase means the creatures whole turn. It can be a slow action, or a move and then a quick action(not a quick attack then a move)

Stumble means the creature cant move.

[Zuberi]

echephron is correct. All creature actions, including movement, happen during a creature's action phase. Once the action phase is finished, no more actions or movement can be had. Even during a creature's action phase, you must move before you perform any other actions. Moving after you perform other actions is illegal.

For further reference, I recommend pages 9 through 11 of the English Rulebook v3.0 and page 47 of the Rules Supplement.