One Routers has IPSec, the other does not.

[JoshGarmonCiscoCCNA]

I was supposed to configure an IPSec VPN Tunnel between R1 and R3.

R3 had IPSec but R1 did not have that mode.

Needless to say my tunnel didn't seem to work.

R1------R2-------R3

Do both Routers need the same mode for it to work?

[johnd2310]

Hi,

What are you trying to achieve? If you are going to great a tunnel between R1 and R3, then both routers should be running the  crypto image, security licence (e.g. ISR2 routers) and compatible configurations 

The following doc should guide you in configuring a lan-to-lan tunnel:

http://www.cisco.com/c/en/us/support/docs/routers/1700-series-modular-access-routers/71462-rtr-l2l-ipsec-split.html