▁the ▁remainder ▁of ▁cont ests ▁involve ▁accus ations ▁of ▁fra ud , ▁ins ane ▁del usion , ▁etc . ▁ ▁The ▁vast ▁majority ▁of ▁will ▁cont ests ▁are ▁not ▁successful , ▁in ▁part ▁because ▁most ▁states ▁tend ▁to ▁assume ▁that ▁a ▁properly - exec uted ▁will ▁is ▁valid , ▁and ▁a ▁test ator ▁poss esses ▁the ▁requ is ite ▁mental ▁capacity ▁to ▁execute ▁a ▁will ▁unless ▁the ▁contest ing ▁party ▁can ▁demonstrate ▁the ▁contrary ▁position ▁by ▁clear ▁and ▁convin cing ▁evidence . ▁Gener ally , ▁pro ponents ▁of ▁a ▁will ▁must ▁establish ▁its ▁valid ity ▁by ▁a ▁pre ponder ance ▁of ▁evidence , ▁but ▁those ▁contest ing ▁a ▁will ▁must ▁prev ail ▁by ▁showing ▁clear ▁and ▁convin cing ▁evidence , ▁the ▁latter ▁requiring ▁a ▁much ▁higher ▁standard ▁of ▁proof . ▁ ▁Cont est ing ▁a ▁will ▁can ▁be ▁expensive . ▁According ▁to ▁a ▁Boston - area ▁estate ▁planning ▁att orney ▁quoted ▁in ▁Cons umer ▁Re ports ▁( M arch , ▁ 2 0 1 2 ), ▁" A ▁typical ▁will ▁contest ▁will ▁cost ▁$ 1 0 , 0 0 0 ▁to ▁$ 5 0 , 0 0 0 , ▁and ▁that ' s ▁a ▁conserv ative ▁estimate ". ▁Cost s ▁can ▁increase ▁even ▁more ▁if ▁a ▁will ▁contest ▁actually ▁goes ▁to ▁trial , ▁and ▁the ▁overall ▁value ▁of ▁an ▁estate ▁can ▁determine ▁if ▁a ▁will ▁contest ▁is ▁worth ▁the ▁exp ense . ▁In ▁some ▁cases , ▁the ▁threat ▁of ▁a ▁will ▁contest ▁is ▁intended ▁to ▁both ▁pressure ▁the ▁estate ▁into ▁avoid ing ▁the