Long term bets are bets made between Marshall and Lily. For years, they kept the secret of these bets a secret until Barney discovered them while hunting for a sex tape in their bedroom (No Pressure) .
The longest running bet was "Lily bets Marshall that Ted and Robin won't end up together." The outcome of this bet teetered back and forth as Ted and Robin dated and broke up. As Ted got engaged to and nearly wed Stella, as Barney and Robin dated, broke up, as Ted professed his love for Robin and then was rejected as Ted realized that Robin loved Barney, as Barney and Robin were engaged and married... Lily continued to prompt Marshall to "pay up!" to which he replied "Not yet."
- Lily bets Marshall that Barney will die by murder
- Marshall bets Lily that Robin will never return their hairdryer
- Lily bets Marshall that Ted'll go bald
- Marshall bets Lily that if Ted goes bald, he'll totally pull it off
- Lily bets Marshall that Ted and Robin won't end up together
- Marshall ends up winning this bet, as shown in a deleted scene from Last Forever - Part Two.